First, breeding is selectively choosing who mates with who, with the specific goal of improving the breed, to make one's birds better reflect the Standard written, described and pictured for the breed.
The rest is mere propagation or haphazardly milling.
I suspect you are serious about making really great chicks. Thus, one rooster for each 3 or 4 females, carefully chosen will accomplish your targeted goals better. You can, if you have two roosters that are very good, swap them out every 4-6 weeks. You can compare the results in about six months as to which matings produced the better birds. We use vet wrap or zip ties to identify the chicks and we keep good records of our matings.
It takes a while, with younger birds, for the matings to be successful. Often young cockerels are clumsy and haven't gotten their skills together. Young pullets, while still producing small pullet eggs, aren't ready to make eggs of the quality needed for hatching better chicks. Wait a month or two or three after a pullet comes into lay before hatching their eggs.
We only leave the breeding pens together for 3 months. That's long enough. Too much wear and tear on the hens isn't a positive thing. We "rest" our hens and allow them to recover from the mating pens. We typically only mate during late winter through spring. The heat of summer isn't ideal for mating.
Hope that helps.
