[Boron]

my formula seems correct .
i now conquered 2 forest provinces in a quick testgame .
i build in each a castle + temple .
when i had low dominion i either got 0 or 1 freespawn .
when the temple was finished i got 1 - 2 .
then with high dominion for 100% i got 2 not more not less .

so first conclusions out of that :
pan cw could try a very low dominion to get a quite high income because freespawns via dominion are quite low .
so just summon one carrion lord everytime you have 25 nature gems .
he can reanimate or research and is a good combat magepriest because of his high undead leadership + high hp .

so you could really try a ridiculous dominion strengths of 3-4 and quick expand and try to outrun your dominion .
this way you should still get in midgame a nice amount of undeads through reanimation and will have a modest income in the dominions where you outrunned your dominion .
this is still bad but you will get more money than ermor .
so you can mix a few minotaurs or something like that in your undead armies .
so far that sounds quite interesting .