Iggi,
You ask about personal experience. I'm a photojournalist and back in 1989 during the last coup attempt against the Aquino gov't, rebel rangers took over the Makati business district. So you had a classic urban close combat action here. I was on a rooftop with a squad of SWAT soldiers from the Philippine Constabulary (PC). Our position came under heavy sniper fire and the PC were returning fire (3 or 4 out of the 12 there).
To make a long story short (I have a full account at: wirephoto.com/lucero) after we suffered one wounded (me) and one dead (PC) our building got hit by a 57mm recoilless rifle. The building felt like it got hit by an earthquake and the dust rose like a fog it seemed. The PC panic and they literally bugged out in 2 seconds flat, with one of them screaming "we're going to be by mortars, get out!"
The rebel rangers in control of Makati eventually surrendered a few days later but if the gov't hadn't negotiated the peace and decided to go in with troops to take them out it would have been bloodier for the gov't. The rebs would have fought till they ran out of ammo or to the last man. Morale on the gov't side wasn't very high from what I could see and mostly were in positions to contain the rebs and although they were firing on the rebs during the hottest part of the fighting in the end the rebs in Makati suffered no casualties but the dead and wounded from the gov't troops and especially civilians were over 150.
So to answer your question from my little experience espirit de corps would be a deciding factor on whether a unit stands and fight even under direct fire from a tank or recoiless rifle fire!
Patrick