Sgt.Squarehead

Date added to the scenario depot is 2016 (part of @Bootie's migration) and this http://www.combatmission.lesliesoftware.com/ShockForce/Scenarios/Mission 3A Forging Steel_v7.html Shows they were created with a CMSF1.x version.

Ok, first off, posting out of context video's of 30 second snippets doesn't really help. Posting all in bold also doesn't do anything to further your point. 
Has anyone posted save games of any of this for other testers to check themselves? It's quite easy to do.
Additionally, was this PBEM already in progress? As in, you were playing the PBEM on v4, then you patched the game and continued playing the PBEM on patched v4? It is well known that applying any type of patch/upgrade and then trying to resume a saved battle may result in some odd behavior. 
I have upgraded all of my games to patched v4, and I have not encountered this bug in any of them. 
My suggestion would be to take a breath, confirm if this is in fact a PBEM that was started pre-patch, and try to post save files for other testers to run and see if they can figure out what is going on. 

Here ya go - all unpacked https://www.thefewgoodmen.com/tsd3/cm-shock-force-2/cm-shock-force-campaigns/usmc-forging-steel-the-missions/

Yup, when a unit decides it needs to relocate, it's more common to have this (decamp/evade/withdraw) waypoint placed forward (away from the scenario designated friendly map edge) without consideration of cover (they will bypass intervening walls/ditches/buildings/etc.) to end movement in a more exposed position. Your screen shot captures this nicely. Some have postulated that variances in elevation may be an important factor.
In any event, having reached this waypoint and should it need to decamp again - it has invariably done so in  a more sensible manner. This being farther back from it's original position, towards the scenario designated friendly map edge  and away from last known enemy contacts.
What I've been doing is reloading the save, selecting the unit that will soon decamp 'badly' , and hitting the Evade to inspect the waypoint it generates. This waypoint is not the same as what will later be generated when the unit does take flight. This waypoint will rarely generate a location forward and towards know enemy positions (this is a good thing). I then Cancel the Evade and generate the turn. If the unit hasn't decamped, I keep generating turns until it does. Sometimes as many as 4 turns have been needed in order to see them decamp at which point they will follow the exact same 'flight' path. As long has they remain stationary - it seems this waypoint is always placed in the same location regardless of variances of known contacts or time (WEGO turn).

I guess permanent pauses (on units adjacent to bocage openings) may be a workaround here? 

Blimey.....It's all kicked off! 

Given the nature of most modern conflicts, these would almost justify a vehicle pack.....Just imagine the things you could create with a few more fully functional civilian vehicles:
"There's an IED triggerman's coming straight towards us on a bulldozer!" 
Or even:
"That bulldozer was dead handy for knocking down all those tall compound walls!" 
Or:
"It's amazing how many conscripts you can cram into a school bus!" 

Hide?   
Nah! 

Yep this is easy, I'll get packaging everything up as soon as I get an hour. We're still waiting for CMmods 4 to activate though. Been waiting for weeks now to upload my new Sf2 UI mod. 

Given the nature of most modern conflicts, these would almost justify a vehicle pack.....Just imagine the things you could create with a few more fully functional civilian vehicles:
"There's an IED triggerman's coming straight towards us on a bulldozer!" 
Or even:
"That bulldozer was dead handy for knocking down all those tall compound walls!" 
Or:
"It's amazing how many conscripts you can cram into a school bus!" 

THIS!!!  @Kieme(ITA) was able to take vehicle textures (if that's the correct phrase) from CMSF1 and make them flavor objects in CMBS (see below screenshots)  If something like this could be repeated for CMSF2 that would solve part of the need for civilian vehicles on maps.  I attempted to import his civilian vehicle flavor objects from CMBS into CMSF2 but haven't figured it out yet.  If you or any other veteran modders @Zveroboy1, @sbobovyc, @37mm or others can make this happen it would greatly improve the look / immersion of scenarios.   Maybe Kiemes mod can just be (imported) made to work in CMSF2???  

Wow! Exciting stuff! And a cliff hanger ending. Brilliant. Can’t wait fir the next instalment. Perfect example of the adage - in any plan the enemy always gets a vote! 

CONTACT 
As soon as 1st platoon dismounts in front of NAI 3, they make contact.

It appears to be a squad sized element split between two buildings. Bradley gunnery is up to a high standard, and rounds are immediately pumped into both buildings before the enemy has a chance to fire at my dismounting infantry.

The enemy is suppressed, and friendly infantry begins to cautiously advance forward to clear the rest of the complex.

Suddenly an enemy ATGM flies out from behind NAI 3 and slams into a Bradley, destroying it and killing the driver.

Moments later, an Abrams in overwatch spots a BMP-2 hiding behind NAI 3 and destroys it with a HEAT round.

Just as suddenly, more enemy infantry are spotted in the buildings, and a close range firefight breaks out.

The firefight is short and violent. No friendly casualties are suffered.

A lull in the fighting momentarily occurs, and I use the opportunity to push up a scout team armed with a javelin to try to get eyes on the second BMP-2 to the rear of NAI 3.

As the scout team is moving up, they are suddenly engaged by the second BMP-2.

30mm HE rounds streak down the road and explode against trees and the ground, though miraculously none of my scouts are hit by the fire. One of the scouts is armed with an AT-4 and takes a shot at the BMP.

 
Unfortunately the shot falls short, but the scouts are able to crawl out of the line of fire and suffer no casualties. The BMP poses a problem due to its positioning, but the encounter could have gone much worse.
A survivor of the Bradley’s barrage pops up and fires a few bursts. This time, the enemy’s aim is good, and I suffer a casualty.

My infantry, as well as an Abrams in overwatch, return fire with small arms and coax. Its enough to finish off the lone enemy soldier.
The BMP-2 is in a good keyhole position, covering down a road that separates my infantry from the buildings on NAI 3. Crossing a road like this is already a very dangerous thing to do, and is known as a Linear Danger Area (LDA). In order to deal with this serious threat, I move Scout Team 3 off of their observation post and down into a position where they can get eyes on the BMP and engage it with their Javelin.

The scout team is able to get into position and take aim. The scout fires moments later, and the missile hits its mark.

On the right flank, 3rd platoon advances cautiously into the woods covering NAI 1. It doesn’t take long to find the enemy. A fire team takes fire from it’s front and suffers a minor casualty. Thankfully, the soldiers body armor prevents the wound from being serious.

One of the scout teams helping to clear the woods pushes up and spots the enemy. They begin engaging with rifle fire and grenades.

Having pinned down the enemy, the scout team capitalizes on the situation and rushes the fighting position.


The scouts kill the remaining enemy soldier and occupy the fighting position for themselves. In this short but violent exchange, I was lucky. I only suffered one man lightly wounded, while killing 2 enemy soldiers and taking their fighting position. The last thing I want to do is get sucked into a costly close quarter fight in these woods. It’s not even my main objective.

Moments later, another enemy position is discovered further into the woods, on a very slight reverse slope.

 
My goal is to quickly sweep the edges of the forest for enemy assets that can pose a long range threat to my advance down the MSR, such as ATGM teams or artillery spotters. Once these threats have been found and neutralized, the infantry will fall back and let the armored vehicles strongpoint the position. That way, if the enemy decides to attack out of the woods, they will be cut down in the open by my vehicles.
Here is an overhead view of the woods covering NAI 1:

This should help to illustrate my intentions with NAI 1. I would need much more than a platoon of infantry to clear these woods, and even then it would be long and bloody. It simply isn’t worth the effort. The good news is, the terrain appears to be too dense for the enemy vehicles to emerge in any semblance of order or speed. As long as NAI 1 is strong pointed by friendly armor, I should be able to keep it bottled up and it will not pose a threat to my advance down the MSR.
2nd platoon (infantry) along with elements of 2nd platoon (armored) and the Task Force command element move forward to establish new overwatch positions along the right side of the MSR.


A call comes over the radio informing the JTAC that the Apache called in on the possible enemy armor concentration behind NAI 1 is now on station. Moments later, a missile is seen streaking into the sky.

The shot came so fast that the Apache pilot didn’t have time to pop flares in defense. The enemy missile hits the Apache, destroying it. This is an expensive lesson to learn. The airspace is not safe for aircraft. Half of my available fire support is now restricted until I can proof the airspace.
However, there is hardly any time to contemplate this new dilemma. The two tanks from 2nd platoon (armored) advance to a berm and discover…

What appears to be an entire enemy tank company in a reverse slope position, at point blank range. Before either of my tanks have a chance to react, one of the enemy tanks fires at Number 3 tank. The round impacts the berm, causing no damage. My tanks are quick to respond. In rapid succession, they pump 2 rounds into targets to their direct front, destroying them.


The exchange is not one sided. Before either of my tanks have a chance to reload, number 3 tank takes a penetrating hit to its lower glacis plate.

The Abrams is destroyed, but all 4 crewmen survive the hit and are able to bail out of the tank without suffering a casualty.
While this is happening, the infantry from 2nd platoon dismount their Bradley’s and begin advancing on NAI 11. They are immediately greeted by a hail of gunfire from enemy infantry occupying the buildings on NAI 11.


The fire causes no casualties, and is quickly returned and silenced by 25mm HE fired from the Bradley’s overwatching the infantry as they dismount.
I’m now in a precarious position. I have deployed infantry and their Bradley’s dangerously close to enemy tanks in a reverse slope position. Further, I now only have 1 tank directly observing and engaging what appears to be a company of enemy T-72s. If the T-72s are able to maneuver out of the reverse slope position, they could destroy a significant number of Bradley’s and Abrams at point blank range with just a single volley. I have tanks in overwatch positions, but they would likely not be able to react in time to prevent a mini-catastrophe.
In response, I quickly maneuver 2 teams of Abrams to either flank of the reverse slope position to keep the enemy engaged and hopefully pin him down/destroy him so the T-72s cannot threaten my IFVs and infantry in the open.

What happens next is pure chaos.

@Bulletpoint discovered the following which I'm paraphrasing:
 If the shooting unit does not spot the friendly unit, small-caliber area fire will kill friendlies. Try it out in a night battle, order your tank to machinegun some distant field and then send in some infantry. If the tank doesn't spot the infantry, the infantry will take casualties. Then order your tank to fire machineguns at friendly infantry that are very close in front of the tank. The tank can fire away all day without causing any casualties.  It also works with rifles.
Not sure if that's what happened in the above case.  I'm just putting it forward as a possibility.  
 

+1  Nice job.  Very interesting map.  I may open it, build a FOB and run some operations.  Some of those compounds look like they need to be searched.................  

Well I will be looking at the maps as well.  Terrain impacts the AI.  Elevation tiles do, too.  They can't be overlooked when evaluating a poor AI reaction when under fire.  An AI controlled unit seeks near-by cover and concealment. It might be tall grass or a slight terrain depression.  At the moment of reaction the AI won't always move away from fire, but under it. This is not to say that all is well and eat your broccoli... Beta testers will be looking at it all from more than just one angle. We are listening.  We will be evaluating and we'll let you know.
Thank you for posting.  It's how things get fixed.
 

Nope, he'd already made 'Halt! Hammerzeit!'  for CM:SF1 back at around the time of the NATO pack (I think it was a stock scenario then too). 
The one I linked to above is the original, re-made for CM:SF2.....You are the Americans (& IMHO, it's a touch easier):

Very highly recommended. 
PS - A certain person started making a Red vs Red version called "Shield of Allah", but then he got very, very distracted.....
 

That's one from @George MC.....It's available in several flavours too. 
The original is probably my all time favourite CM:SF scenario.....Drainage ditch & all. 

That's a very good idea.....With two installs you could do back to back tests too. 
I'm up to my neck in maps (which don't much care about patch level) or I'd do it myself as I am genuinely curious to know what's up. 

Nope, he'd already made 'Halt! Hammerzeit!'  for CM:SF1 back at around the time of the NATO pack (I think it was a stock scenario then too). 
The one I linked to above is the original, re-made for CM:SF2.....You are the Americans (& IMHO, it's a touch easier):

Very highly recommended. 
PS - A certain person started making a Red vs Red version called "Shield of Allah", but then he got very, very distracted.....
 

This thread is only a week old.  That is nowhere near enough time to collect and examine data particularly for TAC AI issues.  You should certainly do whatever feels right for you playing the game, but I would certainly not make any conclusions on cause and effect here.  Making the game "unplayable' seems a bit of an overstatement yet that is a subjective evaluation.  If you feel it is unplayable, then it is.  What I would suggest is rather than delete completely is to do an additional install so you can continue to participate in testing.  As you seem to be able to reliably duplicate the issue, your assistance in validating items could be really helpful.

It doesn't seem to be consistent either within games or even scenarios.....Issues with routing in CM:SF2 are mentioned above, I play a lot of CM:SF2 and I just haven't seen it.  However I point to point my units fastidiously, especially in urban environments, so by virtue of that, I may not be seeing an issue that is actually quite real.

@Sgt.Squarehead Pretty sure that they've been more or less confirmed so far. In the 4.0 upgrade for Fortress Italy, you could see a number of un-selectable factions in Quick Battles. The Brazilians were among them. The devs have corrected this "inclusion" in the latest patch.

Very interresting concept when I can lend you a hand don't hesitate...;)