The first black frizzle is a male, and I think the second one with blotchy coloring probably is too, but I wouldn't count on the rest of them being females just yet. It's still early in the game.
They are a specific dual purpose hybrid bred for fast growth. They can lay well, but they are mostly used for meat by those who don't want Cornish cross or Red Rangers. It is the fast growth above all that makes me think your chick is a Ranger.
The other two possibilities are Bielefelder or...
The bird is barred, and Hoover's doesn't offer barred Wyandottes. I'm not even sure they exist. Hoover's does offer Rainbows under dual purpose breeds, and I am betting that's what this chick is.
I'm thinking olive egger or one of the meat type hybrids like 'Rainbows' sold by hatcheries. It seems off to me for a Bieleflder or Welbar, but hatchery chicks can vary a lot, so can't rule them out.
Their white earlobes aren't very conspicuous, but I think these are Leghorns. Hoover's sells what they call blue breasted brown Leghorns, and Meyer's sells what they call blue partridge Leghorns.
The hatcheries don't sell many layer hybrids whose eggs are white. It's just not a very popular...
Probably a red sex link mix. The white tail is what I am basing this on. Red sex links have the dominant white gene that covers black coloring but not red. However, red sex link cocks are mostly white, which is why I think it must be a mix.
Thai game fowl of some kind seems right to me, but I am far from an expert on Asian game fowl.
I would try to find different stock to breed these with because they may be siblings. If you get unrelated stock you could line breed them. The rooster especially is beautiful.
You could also cross...
When they are really young it's not as much of an issue, but at 5 months, yes, they are going to go after the newbies. You can just put them in there to see how it goes. Sometimes the unexpected happens.
If you do that, it seems to help to do it at night, and put the new ones on the roost bars...
I did a google search on Thai game fowl, and AI gave a brief explanation, but it seems a lot more complicated than the information they have on the topic.
I did find some pictures, but to me the different types all look pretty similar. I'll post a few of the pictures I found.
Basically, I...