African Mbuna should never be mixed with anything than other Mbuna of the same temperament and also not the same color.
I keep my cons in with 2 Oscars, 3 Borleyi, 1 Silver Dollar, 1Bala. Even though they have fry to tend to, they are aggressive only when near the fry. They have established a territory and pretty much do not venture from there. Ther teritory is very small (About 18" radius) and the rest they leave to the other residents.
(The Borleyi are Africans but are peaceful)