I have mbuna (P. saulosi) with olive nerites, MTS and pond snails. They do not bother or even pay attention to the nerites. They do go crazy for pond snails that I smash against the aquarium glass to give them and their tankmates an occasional treat.
If you can find them, I would recommend zebra nerites over olive. They are more decorative and also from Africa.
Olives are drab and functional. Curiously, they do come in olive green and black colors, just like, well, olives.