Excuse me, a little out of topic question: what was the nerf on immo?
Also, what I don't like with the Golems is the lack of synergy with Cremation.
When you have a Phoenix in play, you can cremate him to play another phoenix, and raise the first one the next turn. With Golems, you don't have this.
So, I would keep 6 Phoenix.
(I'm noob, maybe don't listen to me ^^)