Avant-garde modern art siege towers forever.
I know this is probably way beyond the ability of the code but it would be really nice to have say - an item that gave ONE PERSON the ability to operate equipment. I was kinda busy soaking up arrows and trying to keep Gaga from being killed (horribly) but one of the big problems was everyone thinking they were "helping" and messing with the equipment. If battle commanders could buy a certain amount of the control items and assign them to siege commanders it might help with the random team member messing around with the stuff.
This may have been more of an issue since both sides recruited anyone they could get and wouldn't happen in a more organized army, but it might still be helpful to think about.