You may have Metriaclime estherae (the orange ones). Take a look in the profile section under Lake Malawi mbuna and see if that is it. Or post pics in the unidentified section to confirm what you have...
A peacock needs a larger tank. Odds are the other two do, as well.
Peacocks aren't going to fare very well with estherae, even in a larger tank. They aren't as aggressive and are more easily stressed.