I just found out that client rulers actually require vast amounts of upkeep (875 mnai in my game, large unit size) compared to FM's who have zero upkeep. This explains my struggling Hayasdan economy so I've started killing off these client rulers by rushing them into besieging generals. This is a bit of a pain though, so I'm wondering if there are any other ways to get rid of these mnai-guzzling hunks of junk?

I'm open to cheating and console commands if there are any.