It depends on the breed, but I'd despatch them when they are worth eating. If you split the cocks from the pullets, you'll be amazed at just how long the cocks will live together quite amicably.
Think back to when most of the chicken we ate came from the surplus cocks produced from the RIRxLS cross used to produce laying hens. ( Thats if you're that old of course

) The farmers kept the males until about six months of age and then sold them oven ready from the farm gate. The old time farmers coped with keeping lots of cocks together and nothings changed, so we should and can still be able to do the same.
I keep gamefowl and they can prove to be a problem but keeping 'backyard' breeds together until killing weight has never been an issue. Just as hens develop a pecking order, so do young cockerels if kept together from the start.