Does slow feathering always = rooster?

[BrickCoop15]

I have The slowest feathering chicken alive! Maybe not but it sure feels like it. I knew he was a rooster when I got him. He just looks pitiful And he's old enough to be fully feathers He's an Isabelle cuckoo Orpington.View attachment 3212851

I have a similar one. It took weeks for her to even start feathering. She is currently 8 weeks old and still has no feathers down the middle of her back and her tail is basically non existent. At this point, I believe she is a pullet based on comb and wattle color and development.. I thought for sure I had a cockerel based on past experiences with slow feathering chicks.

 

[McChooky]

The egyptian fayoumi are one of the fastest maturing chickens .The pullets can lay at 4-5 months (cockerels crow at 4-5 weeks)