I have a black Orpington who is now 4 mos old and I wasn't totally sure he was a boy until recently when he finally started growing some sickle feathers, not to mention the huge comb and wattles. Still no saddles or hackles, he's WAY WAY behind all of my other roos, all the same age. How old are these guys? They do look like pullets, but if they are only like 10 weeks old, one might start showing some more roo qualities soon. If they are closer to 4 mos, then they are likely all girls. Here's a pic of mine, same age as the other roos. He's by far the biggest, but also the least developed! He hasn't crowed yet, either.
Here's what he looked like 2 mos ago. I really had no idea whatsoever on sex at this point.