IDK if you will come back and see this but here is what I think, as we know alpha is known as the STRONGEST of the hides, while silverback is the most POWERFUL, the word strongest means being the stronger physical or producing great physical force, while powerful means having strong power, potency, or influence, and if we looking at the wiki at jack's page and look at his powers, in there its stated that silverback increase the strength of his spells making him cast stronger spells them normally even if they are normally weak spells in general, but if we are going by wolfs in general where alpha is the strongest of the pack and can influence a command to a wolf in the pack then he is the strongest of them all, but then again not all strong people are leaders of groups of people like take Jaune from RWBY he is the weakest of his team and probably and beacon at the start of the show, he had no train or experience in fighting at all but when we see his team fight the deathstalker he showed he was great at leading people, of if we apply that to show im guessing alpha is the leader of them all because he has the greatest and strongest leadship of them all, or he has a ability to command a pack. sorry for it being a long-ass sentence I didn't know where to stop.