I thought the client ruler problems had more to do with adopting them into the family tree ... the player could simply not do that. The problem is that the computer does build Type IV gov't and is happy to adopt them into their family tree when possible. I wonder if client rulers could be made totally immobile so that they are involved in less fights and so they would be adopted less ... it would also keep us from moving them out by accident and losing all their influence (which they never get back by moving back to the city).