Just a note for information purposes. I have lots of RFA's and a handful of mini maxi anemones. They appear to be completely compatible with each other. Even the tiny kids of my RFA's share a rock with a couple of mini maxi nems.
I haven't noticed the RBTA's wanting to be down low in the tank when they have the choice. When my RBTA's split, it seemed one would usually move and way more often than not, it was off the rock in the sand and on to higher rocks in the tank. It's my opinion RFA's and MM's seem to like being on rocks at the edge of the sand more often than not. I see lots of RFA's when snorkeling in the Keys and most of them are attached to rocks in or very near the sand.