This is just me coping, but if you get caught in an ambush try to fight through to the other side. Keep your foot on the pedal and keep going until you're clear. If you've got buddies trapped in the ambush zone you can re-group and go back in for them and then instead of the enemy attacking you from all side, what would happen if you stayed in the ambush to try to help your buddies, you'll actually be gaining some advantage by sandwhiching the enemy between your force and your buddies. Applies at all levels from infantry companies to bar brawls.
So Arce basically sucks no matter what, yeah? The fact that he isn't cracking down on this suggests at best he's weak as a leader, or worse, he possibly even wants Morales to be killed. It's kinda one or the other, and both are damning.