Hi Erwin,
This mod is not really designed to replace anything. It was simply uploaded as a matter of convenience.
EZ originally created some fine uniform mods; however, the link that he provided no longer worked. Sometime later, mjkerner did some additional work based on EZ's mod (all with EZ's permission and blessing). mjkerner made a series of mods that added shoulder patches and occassional helmet markings from the various divisions that participated in the Normandy campaign, which all look great by the way.
These mods with the shoulder patches cannot all be used at once though. If want to have the 29th infantry division in a battle, you have to put that uniform mod in your Z folder. If you later want to have units from the 1st Infantry division, you have to quit Combat mission and replace the uniform mod for the 29th division with the uniform mod for the 1st division.
Now because the original link for EZ's uniforms no longer worked, the was no longer a way to get the base uniform mod... i.e without unit patches. The advantage to having no unit patches is that you don't have to constantly swap out mods to avoid having the "wrong" division fighting in your battle. It's a generic uniform that works for everyone.
I never had the chance to download EZ's original mod before the link stopped working, but I did grab it once mjkerner released his mod. I wanted a generic verion though and so I removed the uniform shoulder patches for my own personal use. While I was at it, I made a few other minor changes (mostly to the helmets, whereby I added some wear and removed a graphical glitch and some odd shadowing). I never had any intention of posting it online, but then there was a request, for a no-shoulder-patch uniform and I obliged by making mine available, as EZ's is no longer around.
So that's it. There's not really any official or "best" mod. The best thing to do is just download stuff that looks promising, keep what you like, and mix and match as desired.