1. Guess all agree on the feeder personality then.
2. The way you describe DDD upgrade could work because it is more of a fork you choose then something completely out of the players control. Date the feeders and submit or turn them down in the first place if you want to stay the dominant one.
3. Still dislike the personality change idea.
I fear this would become rather incomprehensible.
Please if you do it, make presonality changes optional!
Learning to love how a character behaves and reacts and then it suddenly changes is confusing.