I dont think that its to unusual for them to flare at that age (still young though), it depends on how fast they are grown and what they are feed. (correct me if I am wrong) but I think that high protein diet encourges more aggresion. I have some that are starting to flare at 8 weeks.
It is hard to part with them, a tank full would be very nice, I guess you choose your favourite 10-15 then thin it down from there.