Need help sexing young silkies!

[silkiemew]

Hello! A few months ago I bought silkies and I am curious what gender they are. The two white (#2, #4) and black silkie (#1) are almost 4 months old, where the brownish one (#3) is only 3 months.
I suspect #1 and #2 might be roosters. They fight all the time and are noticeably larger than #4 (same age).
However neither of them have larger combs or waddles which confuses me, but they do have those stray feathers on the back of the head.

Here are some photos.
Thank you!

 

[Notaneggspurt]

The only thing I am sure about silkies is they are chickens Mine crowed AND laid eggs

 

[Crazy for Chickens!]

We really need front comb shots, please.