Well, they are adorable, no matter what! And cuckoos can sprout combs early..even the girls. Some roos get prominent ones pretty young, but dont depend on that!
The nice thing about Cuckoo Marans is that they are color sexable as chicks. The lighter ones are boys, the darkers ones are girls. Can you put them all together and see if there is much of a difference in the shade of their feathering? Some people can tell by the spot on their heads when their itty bitty, I cant though.
Also, alot of times, with mine, the girls were all feathery first, and the boys were still a bit fuzzy, slower to feather, than the girls.
Hope that helps. Your pics look like a flock of girls except for the little rooster on your leg.
Tina