I think you have some hatchery quality Silkies there. They will develop small crests. Hatchery Silkies tend to have more hard feathers in the wings and tail. They tend not to be the big puffballs that breeders of Silkies produce. They also tend to have all sorts of flaws like only 4 toes on one foot and 5 on the other, wrong color eyes, little to no footfeathering, incorrect color and type of comb.