As suggested by ktolen:

Would it be possible please to also allow the Contributor role to create/edit a Campaign page, but not publish it. Similar to Contributor <> Posts

Background: GPI wants to allow campaign teams to have their own content on the production environment but not allow them to push anything live until we can ensure it has had the proper Legal/Comms sign off/review. The auto-sync of the release site makes it impossible to use it as a staging/review environment.