Not all females will accept all males. I have read in several places where hens can reject the males sperm. I personally have a silkie hen that has killed a couple of silkie roosters, and never gave me a fertilized egg off of those roosters. Good luck getting them together.
The cockerel with the single comb looks to be a mix, the barred cockerel with the pea comb beside him looks like an ee or olive egger (small feathers on his shanks) the brown pullet looks ee and the first sumatra looks mixed (shouldn't have the red/brown neck) but a good side shot of each...
They are mixed breed. Sparsely feathered shanks, whitish earlobes, body type, and the type of comb give away that they are not sumatra. Sumatra should have a pea comb, dark to black face and legs with yellow feet bottoms. No feathers on the shanks and the ear lobes are dark to red but not white...
I've had chicks with yellow up their leg end up as adults with it only on their soles. Hens with yellow skin will lose some of the pigmentation as they go through their egg laying cycle. When they molt and stop laying eggs for a while, they will regain it. Age and health of the bird can affect...
Sumatras are to have yellow feet bottoms as they have yellow skin. A bird with white skin has pink/ white feet bottoms. White skin on a sumatra is a DQ if you are looking at showing your birds.
Most sumatra chicks are not solid black, but have some cream fluff also. Sumatras also have yellow feet bottoms. Your black chick almost looks to have a small crest possibly coming in. At this moment I'd guess a boy since it has a bigger pea comb, but I could be wrong. Good luck with your chicks.
If you decide to show, be careful not to cross your breeders/ show stock with the fibro crossed sumatras as it would make them DQ. Sumatras should have yellow skin, thus the yellow on the underside of their feet. Good luck with your birds no matter what you decide to do with them.
There are several people who have already done this cross. You might be able to find some for sale. Through, since you mentioned that you got your sumatras from show stock, are you planing on showing your sumatras some?