I don't know this breed at all so no idea how much comb they should have etc but going by the way they are standing up,tall and proud with tails erect alone all I can see if one girl at the front and a whole heap of roosters.
To sex a chicken what people are looking at is the length and shape of the feathers on the neck and to see if it has started growing longer feathers on it's back right before the tail. If they have all started growing those and it this age they should be fairly obvious if you look up close they are boys.
If you can take a photo of one of the more upright ones neck feathers and a photo of that one at the front with its comb turned to the camera you should be able to see if the upright ones are different so you can then compare that to the rest.
They look like White Leghorns. It's too hard to see the if they have pointy saddle feathers. Big red combs does not mean they are cockerels--in fact, I think that any with floppy combs are probably your pullets.
I am certainly no Leghorn expert but I have a raised a few and I am hard pressed to say there are any cockerels in the bunch that I can see. I would say you have a nice bunch of pullets there for my two cents. Best of luck and enjoy all those large white eggs they are about to lay.