Actually, I am against having to downgrade your army in the 1st place as it leads to people making low AP warbands with a perfect synergy in order to force their opponent to screw over their warband leading to low AP unsatisfying battle...
In other warband-based TBS, they give an "underdog bonus" to the warband with the lowest score/AP at the end of the match. Like bonus XP (XP/Renown), Cash (Ducats) and or Gear (maybe better injury protection ?). That encourage players making the warband they want/can make and would lead to more enjoyable battles.
Naturally, the rsk/reward needs to be tweaked in my opinion. A lost match should give roughly 50% or a win in order for making playing a match really worth it. Would decrease the need for using "hacks" for those who really cant deal with loosing a match at the moment.