[Gameplay: Units] Arranging Units

I've been digging through here and haven't seen a post on this. So please excuse me if there has already been a post.

I'd like to be able to arrange units in a formation before they engage in combat. Even just a general marching formation or champion party travelling arrangement. Like placing my melee champions on the front line with casters/archers behind them. Just some simple options when I form a group/army or what not. Perhaps have a variable that when I'm attacked, random placement happens (like now). Make modifiers that are based off of a soverign's charisma or something.