Adventure mode had BETTER have faction-distinct variations. Chaladon would prbably have everything lighter, faster, squishier. Anglea would pile on speed and armor. Arashi would focus on armor at the cost of health, and slowing speed in return for accel. Merchants would try to have everything kind of all-rounded, Yesha piles on health AND armor at cost of speed, Baronies might have higher accel and health.
Did I get everyone?
Oh, also having a set number of availible guns, but more slots to put them. So like, having a light gun slot on each side of a galleon, a front mount light gun on a gally, having a back mount gun on spire, changing a side gun mount on the Pyra to the other side...