[Executor]

Well dominion is a matter of playstile, if you're going for the saurolich you do want a strong, probably 9 or 10 dominion logically. But I had 9 dominion in my last game with MA C'tis, and it was a problem to say at least. I had multiple threat like "if you miasma dominion spreads we will attack you". And I did get attacked by multiple enemies. Having 9 dominion and an awake pretender spreads dominion like crazy. Taking 7 instead of 9 is only a 2% income cut-back. I also like to take growth but like I said only for larger games.
As for Lamia Queens, while you can get blood with them, I don't think it's certain, so wasting 25 nature gems for a commander that can maybe get a little blood is not good when you can use whose gems for GOH, GOR, ring of regeneration... You'd be better off blood hunting with regular unit, I read somewhere that they have a 5% chance of success. Tried it once and empowered a mage to blood 1 and so on. (but took too much time)
You will surely get blood tartarians, but it' hard to blood hunt with shattered soul, they can pillage and destroy the lab, especially if you have more than one in a province.