They couldn't be too large a number, less they start to become expensive and potentially powerful in their own right, so they'd need a technological and military advantage. They'd need to be organised independently in a way to make it hard for them to work in tandem. I'd seek to have a military, to service society, filled with this group of cultural warriors and defenders of the faith. Only under the right directions would it together be powerful. Amongst themselves, if they were to turn, they would be in this disadvantaged position.