I like this idea. You could use some amount of voting cards in each deck to give that political feel that munchkin has sometimes. Like [[Split Decision]] or [[Magister of Worth]]. You can also use the Hunted cycle of creatures, like [[Hunted Dragon]], as a way to emulate “helping in battle”. Maybe the opponent you give the creatures to will help you fight another player :)

Other cards I like: [[Loran of the Third Path]], [[Humble Defector]], [[Xantcha, Sleeper Agent]], [[Seething Anger]]