Hatching new chicks, what should I expected from BR roosters?

I posted a similar thread to this a couple months back so sorry if you read that I hope I'm not repeating myself.

My friend has one rooster. He had 6 hens but over the winter he got raided and now he's down to just his solo rooster. We decided he needs some girlfriends so I was going to use my incubator and hatch out a bunch of chicks for him. I have a few different breeds from my adult stock(RIR, golden sex-link, white leghorn, etc) and a barred rock rooster. Will my chicks all look the same or will they be distinct looking based on which breed laid which egg.

He just wants hens for his rooster so he doesn't care about appearance but I was also curious for my own knowledge. I think I've read somewhere that the barred rock genes will be pretty dominant and most the offspring will sort of look like dad.. but I never verified how true that was.

Thanks