Sexing orpingtons, marans, polish

[Japetus]

I'd appreciate some help towards sexing my 8wo orpingtons:

Also is there a chance to find out at this time the sex of the - also 8wo- silkie on the left?
What about the araucana at the right? Is it a true bred or a mutt? I have no splash birds in my (true) araucana coop, only silver and black chested reds. Could he come from my other, a mixed breed coop, where I also keep an araucana rooster with the egg laying hens?

. My polish, around 8wo also. Can't be seen from this pic but one holds its tail mostly vertical and the other horizontal.

. 5wo BC Marans. The one - likely a roo - has a bigger red comb and wattles but the other has a much darker, almost black comb. Is it normal for the breed?

 

[The Happster]

Hard to see the photos properly.
I think you have one Maran cockerel, two polish pullets and the buffs....are they really 8 weeks???
They don't have enough comb for me to think definite cockerels, but to me they look like older pullets. Nearer laying age.
Plus the head shape and face scream pullets.

 

[The Happster]

At a guess I'd say the Silkie is a cockerel and the EE a hen, but the Silkie is too far away from the camera to be sure.