
With a good age gap like you have unless the breed tends toward same sex intolerance you should not have a problem.
By the time then youngster reaches and age where he might get a bit cocky the older one is mature enough to be secure in his higher position, and the youngster is unlikely to challenge him for no reason.
the main reason for male disputes would be the presence of an entire bitch, especially if she is or is due/has been in season.
Also introducing an adolescent or adult male to an existing male can cause problems, but a young pup will hero worship his companion and know his place.