A comb that size and that light color on one of my reds would lead me to think pullet. But I have no experience with SFH. The brown one's comb is bigger than the black two's combs. That might point to a roo.
you really can't compare different breeds, since they develop at different rates, some have larger combs than others, etc. so it's like comparing apples to oranges.
my bantam cochins are often crowing by 4 weeks old, while I may not be able to sex the sfh until they're 6-8 weeks old or more and cockerels don't seem to crow until at least 12 weeks most often.