I've been a priest in a Realm-Religion and we did get a lot more involved in the wars.
I've also been a priest in religions that spanned continents. Sanguis Astroism over in Dwilight. I was one of the priests that helped write their ten or however many prime tenants. That was fun. But we were divorced from the realms because we were priests first and realm nobles second.
My current priest is the High Priestess of Daishi. That used to be a realm-religion started to protect the core of a nation after there was a rebellion and the priests went over to the rebel side and started driving the loyal regions rogue. It morphed into an anti-Daimon religion when the Invasions came, and the Daimons did everything they could to wipe the religion out entirely. Almost succeeded too. They just missed one temple. After that, Daishi became a non-realm religion and is now the dominant religion of the continent. I could go into any realm and destroy them if I wanted to. I have that kind of power. But as Daishi is purely an Anti-Daimon religion that does not interfere in temporal decisions, everybody knows I won't do that. So all the other religions have just faded away. Nobody fights Daishi because Daishi doesn't fight them. We are just...everywhere.
Daishi actually covers a similar role the one the League of the Eagle does on Atamara. The League has people from every nation in it and it is the quickest way for people on one end of the island to talk to the other side. It is the same with Daishi. We have nobles from just about every nation in our ranks. Heck, there are two of us who share the top position in the religion. Our nations have been at knock down drag out fighting war for as long as either of us can remember. We never have a cross word for each other.
