FM beta tank mates that work.
I have a beta sorority of 5 FM betas that are very happy with their tank mates in my 55 gal tank. Tank mates consist of 6 cory's, 6 Tiger Barbs and 6 Serape Tetras. Tank is heavily planted with lots of hiding and escape type places. They have been together for a several months now and don't exhibit any problems with each other or their tank mates.
It's one of those things you have to try and see how it works out.