Idea: Raid warclaim, lowest tier. Allows for one large attack directly on the city as a big ass raid. No limits, no allies, no damage, theft of specific items but no wanton looting of chests. Month or two cool-down. No CB required.
I remember getting raided as an Orc by like 40 or more Dwarves every time, and we still won the raid half the time with like 15 guys, It was ******* fun, and I loved when they raided, even when we lost.