I don't plan to show my birds either, but still want them to resemble their breed standard, in size, correctness, and lack of defects. For cockerels, temperament is my first concern, and physical defects, fir example wry tail, beak deformities, or bad feet. For breeders, never being sick matters a lot too.
Once you separated these tow cockerels, they just aren't interested in getting along together. your breed tends to have many 'tough' cockerels, both with each other, and with human aggressive tendencies.
@Beekissed ,
@BantyChooks , and
@Shadrach all have good article about managing roosters, well worth reading. I think that the cockerel jumping you from behind is not behaving well, and when he's grown, with nice spurs, it won't be harmless!
I want my cockerels to pay attention to their flockmates, and not go after me, ever. Reforming jerks usually fails, and just isn't worth it. Nice polite roosters are wonderful, not the other sort.
One or both of your cockerels might work out for you, or not. See how things go, and don't feel bad if neither turn out to be keepers. In spring, more chicks, and find one or two good ones!
Are you committed to this one breed? Try some others!
Mary