This is why I highly encourage a few (2-4) religions per island (the opposite of my encouraging many realms). But folks all want to do their own thing instead of cooperating with others. Religions are meant to span across many realms, not to have a religion per realm.
To be fair, the Phoenix faith (pre-Path) -was- supposed to be adopted by Alara and a number of nobles from other realms, as well as my planned Xavax offshoot colonies. Never happened due to !!POLITICS!! but such is life.
Anyway, I'd go so far as to claim the religious aspect is integral to the full Xavax experience.