I have realized something w/ my baby guild (which I thought was deleted but wasn't.) As more rerolling has happened, I noticed that the leftover members were not auto-promoted. So, if you delete a leader, the highest rank you will have is 9, if you delete 9s, the highest you have is 8s... etc, and you can't promote beyond that. I asked GMs in game to fix, but they said they can't. This could be an issue! But obviously better planning would make work arounds possible.