I have donated a few tiny Dutch bantams and a bantam RIR to several chicken owners who had standard commercial laying hybrids. I saw /heard they got along well immediately or very soon after arriving.
I didnt keep in touch with the new owners. So I don’t know if the tiny /small roosters could fertilise the hens. The people who took my cockerels, mainly wanted a rooster for protection (alarm) and fun. And a small rooster is easier to handle. Also, Dutch bantams roosters look stunning with their large tails.
