3 month old rooster already trying to mate?!

[Eggs_Over_EZ]

We have a a Buff Orp that is doing the same in Hoop Coop II. Only hatched in late April. There are several other cockerels in the coop with him, including other Buff Orps cockerels but only he is trying to mate. Yup he was from the 10 replacement chicks Royal King gave us for their error of having Isa Browns labeled as Buff Orpington. Out of the 10 “female” chicks 4 are male. I understand errors in sexing a day old chick is not easy but 4 males out of 10 is ridiculous. I can have those odds hatching my own chicks.