Been playing tons of that Caribbean warband mod expansion lately. It has a pretty decent pre-battle and battle formation system. By pressing the TACTICOOL MAP key, you can move around squads or groupings of your dudes according to class (musket, melee, cav, etc). You just click on the nifty little square representing those dudes (its got 2 cool cross swords for melee dudes) and drag it elsewhere on the map.
Battle AI (ESPECIALLY targeting) is pretty fucking abysmal in the mod, but that formation thing is lovely. You can certainly pull off enfilading fire on bad guys, wide cavalry flanks without using FOLLOW ME and dragging them along with you, etc.
