iv had mixes of gender of peacock and mbuna in the same tank, as long as there is always a 1m 3f(minimum) ratio.
having female peacocks the same colour as a male mbuna (for example) obviously they will hybridize. as long as you accept mixing mouthbrooders will probably end up in hybrids, u can keep almost anything together. but its all individual personality and a good dab of luck for the perfect agression levels for them to be active but not attacking.
male peacocks can be worse than mbunas (with auratus as the exception) so its best to have a tank mostly females. mbuna have the best colour females, zebras for example. OB zebras especially!
or have an all male tank, but these can be hard to get right with some looking male but being female and causing a massive uproar of competition, or some 'bad sheep' x