Views are short coming ladies and gents
Will just one m/f of the above peacocks be OK as the Afra's and labs are safer as dthoffsett said being omnivores.
Yes, they seem fine! I have two male peacocks on a 75g tank along with about 20 mbuna. All the mbuna (apart from 3 acei) are about 2-2.5" long, whereas the peacocks are a good 4" and ironically the most alpha fish in the tank is one of the peacocks, inspite of what they say about "peacocks will live in a constant state of subordination." This may be true if mixing peacocks of the same size, I don't know. I have a male auratus that runs from the peacock. Again this may all change later on when the mbuna are bigger I don't know. But now they all seem fine!
The main problem, I found, was mixing multiple male peacocks. I tried to put in two smaller male peacocks and had to rescue them as the two other peacocks didn't like them. I should have done my research, but I found that male peacocks should not really be mixed full-stop.
What is interesting is I have an orange male aulonocara, and he will get chased by a smaller red zebra, which is also orange. It's mild and the peacock doesn't take it too seriously, it seems.
I would say go for it!
Also, not sure if a 1m/1f ratio is good for peacocks, as is the case with mbuna. I'd try a 1m/2f minimum, to disperse the males aggression.
L
PS. All the LFS tanks have mixed mbuna with peacocks and other haps. They say they never have problems. The other thing, they say the dietary requirements issue is blown out of proportion. They claim to feed their fish tetra prima (protein food) as a staple, have hundreds of mbuna, and rarely -- if ever -- see a fish suffering from malawi bloat. They say it does happen, but is extremely rare for them. Of course, I'm keen to give my mbuna lots of vegetable based food, but I'm also not averse now to giving them a regular feed of protein based food, such as tetra prima.