There's no one answer here. Cockerels may continue to get along, or not. If they get along this year, things may really escalate next spring, and require adjustments.
More space is always better!!!
You really aren't going to keep three roosters of the same breed? There's no need to do that! The trick is in choosing the right one or two to keep. It's nice to have a 'spare', but it does require more space, more hens, and no serious fighting.
My adult flock has four roosters and currently 37 hens, both bantams and standards, and they have a coop with separate areas that open to each other, and then they range outside. There's very little sparing, even when they are all locked if for some reason.
I plan to sell one of the roosters, and keep a couple of this year's cockerels, and see how it goes.
Mary