Realistic definitely. Cinematic portrayals frequently appear retarded. For instance, everyone lines up like toy soldiers, one side fires a volley, then they wait about 30 feet away for the other side to fire a volley, then they charge. If one is going to charge it should obviously be done before the other side shoots you in the face.

I would hope that there is a proper skirmishing system, e.g. that if one sends a column on the attack some of its members will detach to form a continually replenished defensive vidette around it.