I dunno, if I was Tom I'd consider making it impossible purely on the basis of the fact that pretty much everyone is guaranteed to try the second one of them is sighted somewhere. They could end up spending 90% of their time in someone's dungeon...
I'm more interested now in this 'Nightfall of the North'. Different family judging by the name, which makes me wonder if perhaps the other invader factions will get their own emissaries/prophets. To my knowledge, the monsters and undead didn't attempt to create religions, so they won't be priests I imagine. Interesting...
