I've kept Mdoka and Mbuna in the same aquarium and they got along fine. The fish were small and about the same size (2-3 inches) when I added them to the tank. A lot will depend on the size of your aquarium, the size of the fish and having plenty of hiding places. When I did this the fish were in a 55 gallon aquarium for about a year. As they started getting bigger I moved them to my 125 gallon tank and they still seemed to do fine together. I've also found that my Cichlids seem to get along much better in a aquarium with a lot of fish in it. I have several aquariums set up so I can always move fish if they're not getting along with each other but rarely have to. If you do try it I would look for Mdoka's that are a little bigger than your Mbunas and use a 55 gallon or preferably larger aquarium with plenty of hiding places. If you try it let us know how it goes.