Counting left to right, top to bottom- photo 4, 6 and 8 are the cockerel contenders to me based solely on comb size and hint of color.
How to determine, guess sex right from the hatch is to look at the leg size of the chicks. The largest legs likely contenders to be male. Nice females will surprise you with good leg size too but still a good indicator.
As the birds grow and start to feather in (most breeds are able to be feather sexed) the females wings will fill in much faster than the males. You can find photos of primary and secondary feathers and search in this forum or online on specifics of feather sexing or just go with visual of these birds have all there wing feathers before these birds- if your birds are feather sexable then females have wings first. Australorps are feather sexable but as these are Blue variety it's unkown what breed was used to introduce the blue gene.
Then your looking at red color in the comb. With most breeds the males start to gain color in the comb around 5 weeks. Pale orange and such is not the color. You'll see definite pink that will brighten to red in males. Females do not get that color until point of lay.
Pea and walnut combed birds are tough and Wyandotte females tend to have color in comb early. But putting every visual clue together will usually guaranty accuracy of sex earlier than waiting for a crow or side saddles to grow.