I'll be completely honest, you could add whatever you want in that tank and see what happens. This is what's in my 55
2x Venustus
2x Yellow tail acei
2x bumblebees
2x yellow labs
2x Ngara white tails
1x Demasoni
1x OB Peacock (with no problems!!)
1x Julie Regani
And 2x Mollies
I have no issues, none, zip, zero, nada. The only issue I have ever had was a 3" Acei didn't like the 5" Tinfoil barb so I took the barb out. There is also a Red Ear Slider in there. Again, no issues.
Is it guaranteed aggression will never happen? Nope. But, I am prepared to make the necessary adjustments when it does happen. People ASSUME a peacock would be tortured or stressed but this is not the case. He came from a local breeder around 1.5" and is doing great with the mbuna. Coloring up more and more as the days go by. Same situation with the Venustus (Hap). You're going to make mistakes, every one does. Just be sure to correct the mistakes BEFORE disaster happens. At any given moment I can move a tank and have 3 choices of where to put it.