Wismar, once again, the game is scaled down. It's not meant to be 1-on-1 historical accuracy. Do you honestly don't know that? I agree that it's not a 100% accurate portrayal of historical accuracy, but the fact that you can bring your lines so close without the men charging off is also inaccurate, and you don't complain about that.
If anything is inaccurate, it's the fact that the third, fourth and fifth rank are shooting. They'd be shooting their own men.
Besides, if anything 'realistic' should added to this game, it's that units have the ability to break without a single casualty. Just because they are all new recruits or a cannonball hit the ground in front of them. Or breaking after their own volley. Or because they hear (their own) artillery fire. That all happened.