I guess I got lucky...my Mbuna didn't eat Corkscrew Vals.....the vals didn't like the low light I have over the tank though, but never showed evidence of being eaten. Hygro on the other hand was mowed down....but I put it in there for them to eat or not eat, so I didn't care. :icon_rollIME, depends on the vals. Corkscrews = lunch. Jungle vals are tougher. Even my Evil Acei wouldn't eat them.
You might want to get a few more females for 2/1 or 3/1