I'd agree on the last two being Pioneers or Dixie Rainbows or whatever similar type that particular hatchery sells. I'm still thinking all hens, although that last bird looks pretty mature, I'd expect to be seeing something a lot different if she were male.
How positive are you on age? They all look like hens, but that last bird especially looks older than 4 months.
Hatchery Rhode Island Red
Red sex link
Two mixed breed birds.