Overstocking of Peacocks and same species haps will result in high aggression or death esp. the eye-bitters. My eyebitters territory is about 40 gal and growing........the fish will dictate how many you can have they can only run so far in 7-8 ft of tank.
I have a lemon jake, red shoulder, bicolor 500, and a eurkea red ............the eueka red stresses the rest to no end and has killed a ruby red also had to remove a strawberry and 2 more lemon jakes that got really wooped on.
hap's - giraffe, eyebitter, ahli,fenestratus had 2 giraffes 1 dead @ 6-7" also had to remove a hyenna and 2 biglips that got smaked down.
In another tank I have an overly aggressive Empress that beats on a tawian reef and a fireline mloto...............like i said the fish dictate who and how many.
With that being said I'd still drop a malawi trout in if I came across one...............aggressions half the fun