I'm more inclined to call them Acaras than GTs. They are easily mixed up when young so I could be wrong with the few pics given. I think a fairly safe bet would be calling them either GT or Blue Acara...or a mix of both. Did they have any orange on the tail? Def not JDs though.
And agreed with the peacock ID. The type would just be sp like said above because trying to pinpoint it from a place like petco is next to impossible. The lines have all been muddy the chances of finding a pure blood is like a needle in a haystack. Ruby Red, German Red blah blah....its a red peacock, male for sure.
Those 3 that look like SA cichlids could be anything. You've gotten some good guesses, but I don't think any can be I'd correctly at this point. One in the 3rd pic at the bottom does kind of look like it has red on the tip of the dorsal fin which could be a JD. But the black dot on it makes me think it isn't. The middle one in the 3rd pic reminds me of a GT, but the roundness of the mouth/nose makes me think acara. The top one in the 3rd pic has what looks like a flower line down the side, and has me totally stumped. Plus it looks like it has red eyes.
I have not been in a Petco for awhile. Are they selling hydrids like FlowerHorn and Red Texas like Petsmart now?
I think they looked stressed. I can see some spangling in the eyes. Not much, but they look very small and very stressed. JD and GT were my first thought when I saw them. Changed my mind, then changed it again. Not sure why I'm even still posting on it. This was an interesting thread. I'm out though..