Well, dominant copper would actually be sexlinked because it's a cross between black copper Marans rooster and barred rock hen.. with the sire having more input to the shade of egg laid in offspring. He looks exactly right.
For me, there might be more than 1 cockerel in that group.
Usually somewhere between 12-16 weeks male specific pointy saddle feathers will start to become obvious in non hen feathered breeds..
Example from google..
View attachment 3222934
View attachment 3222936
Sometimes pattern can make rounded feathers look pointy.. placing your hand or a sheet of paper behind them can make the shape more clear.
Your one EE, has a nice light shade face still and is the only one I wold comfortably call pullet. (maybe both, I can't tell them apart.