their faces seem a bit too overreactive

Considering the situation they’re in, I’d say nothing is an overreaction. The faceposing does look off though, try to focus less on it.

I actually do like the hand posing you have going on. that outstretched thumb from the guy reloading looks realistic without over doing it imo. I also like the posing of the guy running back to the trenches. However it seems like every soldier that we are on the side of are all evenly lit. They’re even kind of bright if you ask me. With a gray day like that and that muzzle flash it doesn’t make sense that they would be that bright nor they all be evenly lit.