They are less aggressive in a group not that they will fight because the 3 varieties of cichlids are Tropheus belonging to the same family and they are Tanganyikan cichlids.
Boozeman, you do not find these cichlids in aquarium shops, I think they are more of the high end type. As for specifics of the tank, pls. ask Sas, he will be able to tell you. I only supervise his work
and make sure it is done.