Believe it or not, with as many Roos as we have around here, it is very seldom one gets rung for being aggressive. I have a Rhode Island White roo that runs with the free range layers thatwas borderline chicken noodles about a year ago. I threw him in the cockerel kill pen to be ahead of the 8 ball. I killed about 15-20 Roos that morning before my son lost him and he got out. He's still kicking it and turned out to be a pretty good roo.
Saw the error of his ways first hand. Lol
Most of my Roos don't get a chance to develop to the mean stage. I find them much easier to process young. So far the ones I've kept are doing good. One eye on them at all times.