Nice tanks you've got there. I rescued a guy from the LFS who was in a tank with platys. I don't know enough about them to know for sure that all types are the same. The betta got ripped to shards by them in that tank. He's growing out now but my oh my. These were neon aka Mickey Mouse platys--cute but--nippy. I got some for the tank at the park where I work and they are busy active fish and maybe not suited for long-finned tankmates. Otos go with betta but keep the size of the tank in mind. They really DON'T mind being on their own--king of their worlds.
when i first got into fish my lfs told me i'd be alright to put a fighter in with my swordtails (close enough to platys) they attacked him which i thought would stop once they got use to him but no i left him for about an hour but then my danios started having a go at him aswell i seperated the tank and put him on his own but by then it was too l8