If you read the theme. I know it's a stretch, reading that is. It says that the Sauromancers reanimated those priests and priest-kings that were locked away in the desert tombs. Noone needed to teach them, they are/were dead and that is where they learned how to bless and function with the undead, in the realm of the dead.

I didn't answer my questions, it doesn't add variety at all, since one other nation can do it already. You want to make the only two living -non- pop killing dominion nations exactly the same?