Bounty List
why not make a tab maybe in barracks or general.
You can make the rewards anything you want, treasure/resources/gold/coins(?)
When you add somebody to the list, their alliance doesn't appear next to their name, so people won't be intimidated by it( like if it was an AoD/Fc member)
when a bounty hunter attacks the target successfully with a sufficient pillage(or maybe loyalty drainage?), he/she will get the reward.
when the target is off the bounty list, the name of their alliance returns next to their name.