Simple comparison of the possible roosters and possible hens says you have NO "pure" breed chicks other than the possibility of Lavender Orps. Never had one but I think none of your chicks look like they have that coloring.
Of all those breeds BAs are the only ones I have personal experience with. Were the last two black and white? At 1 month a BA would likely still have a fair bit of white on it. And they have very dark eyes. Maybe a RIR/Orp mix? But those slate legs are likely BA, Ameraucana or MAYBE a BCM? I'm seeing references to slate legs on them (like BAs) though there are also references that say they have feathered legs but who knows if they are mixing up FBCM with BCM. And is the person you got them from mixing up FBCM with BCM? So MAYBE a BA/BCM mix?
I agree on 4 & 6 being cockerels, those are some pretty serious combs at that age.
You are right, the game is rigged, no matter WHAT people guess, no one will ever know for sure
