One of my 75s has a male GT and a smaller pike cichlid, they do fine together. Also a delhezi bichir, I'd add more polys if I could find them for sale.
The other 75 is a planted tank with uruguay fish - Crenicichla minuano, Gymnogeophagus sp. paso pache II, and Gymnogeophagus balzanii. No aggression other than the males occasionally chasing the females of the same species.