Hiding places are good, and you will generally be ok with small numbers so long as they are juveniles. How large is your tank? With mbuna, the generally stocking suggestion is 1 male with 3 or 4 females. With Kenyi I recommend a 6' tank and a large number of females, and a single dominant male. I have found that Kenyi are extremely aggressive and once they get bigger, I've never had long term success with them, always ending up with just a single large male or female of the species left alone by itself in the tank. It is really to bad they are so aggressive, as they are extremely pretty fish.
Just so you know, that male is sexually mature - which means you need to acquire more females ASAP.