Saul and Jolene wondered about multiple GMs running a campaign together. Not at the same time but alternating GM between adventures or story arcs. When Jolene searched on the subject most of the hits were about GMs running the game together.
Saul has had a few experiences with co-gming one successful another not so much. For the most part Saul and Jolene think Co-GMing could be a good thing if you do work before the games begin.
Music by Izzy Iz Zuddin, song Friend or Foes, from the album Nocturnal Personalities
Available from Tribeofnoise.com