What size tank are these eye biters going in and what will be the tank mates? (keeping them with mbuna's isn't recommended due to aggression and dietary differences). Anything less than a 6ft tank would be inadequate. They get fairly large and are active swimmers. A 1 inch eye biter will be 6" in a year (and will still only be half-grown as far as size is concerned).
As with most polygamous-breeder african cichlid species, the fewer the females the greater the aggression/amourous attention the female(s) will receive.
1 female with an over-eager male will receive 100% of that 'attention' (which may range from receiving the male's breeding displays to receiving the male's aggression since certain male african cichilds do not take kindly to unreceptive females).
2 females/1 male reduces that 'attention reception' to 50%, with further reductions for each female added.