rd can live with other fish in a big enough tank, 180g+ and you have a good chance of finding some robust cichlids to live with it, trouble is they grow faster than pretty much any cichlid up to 6-7 inch become dominant and go on killing sprees... it will claim the entire tank in a 75 though... i have a 12 inch midevil/midas and 11 inch butti living together in a 300 with two oscars anothe midas female and a few catfish..
on that list lose the mayan, jag and rd and replace with something like a green terror, severum or blue acaras and you will have a really nice setup.