I think square is fine in game, it helps inferiority repel cavalry batter and that seems all it is good for, which is fine by me. Also when a square is fighting off cavalry it seems to try and keep its formation so people seem to be moving about it so there probably a bit distracted to fire and reload.

Maybe it should be 3 ranks deep but that would have probably made them very small in the game, and one hit with an explosive round form artillery may wipe out a unit, that would not be nice.