Maintaining consistency of a story between multiple GMs is incredibly difficult, especially when the story has a span as long as the Zuma's. Just look at what happened with Vates: He created so many storylines for the Zuma but did so without collaboration from Haktoo left no usable notes behind for Haktoo to work with. Or you could look at the disaster that was Netherworld in the fourth invasion where some GMs out right refused to work with others.
And, finally, finding people who have the time, ability and willingness to take on the role of a GM is not easy. It is hard, thankless work where you will hear about everything you do wrong and very little about what you do right.
I have already made a plausible response to how to resolve this.
Multiple, rotating GMs with overlapping "terms" and a broad understanding among players that the daimons are truly different, with different goals and knowledge, not merely contrived personalities. Make it essentially like a human realm, except played by GMs.
Poll