[K]

This seems to be one of those "the theme has nothing to do with the actual play."

You need high pops for resources for all your troops and for blood hunting, and for the gold to buy your expensive troops and to offset provinces set to no taxes because of the blood hunting. You have old fire mages. You can spread your Dominion really well with Blood sacrifices.

None of that says "take Death."

In fact, I'd argue that the theme is more "can survive in someone else's bad Death Dominion."