Other notes that I have after doing some more testing with various combinations of CBM 1.6 and this mod:
EA R'lyeh loses their slave troll recruits with this mod. Now personally, I didn't even know that CBM gave them slave trolls, but there you have it.
with EA Atlantis, CBM gives Living Pillars 12 MR. Enabling UWGIM lowers that to 10
It really would be nice to get the Coral Priests back at perhaps UW-only castles as Squirreloid mentioned. It would give a certain reason to spam castles underwater. Also, the Coral Priest is the only worthwhile commander Atlantis can get for under 200 gold.