From the slide it sounds like all chicks are going to be mixes, and those are the pool of parents it could be. I have to wonder how many roosters are involved in the parent pool, because if only 1 or 2 that would give you a good leg up on the parentage.
I'm not great at sexing though I suspect it is too early to tell for these chicks. Enjoy them!
You could only tell at this age if it was an auto-sexing breed (which is a breed that has signs at birth to determine sex, when purebred), or if it was a sex link (which are two specific breeds bred together that show signs of male or female at birth). I'm not sure we could tell anything if we weren't clear about parentage, but you can write back with photos at around 5-6 weeks.