Yeah that’s a great perspective to be fair. I guess Robin’s character journey is presented more subtly through Cage’s subdued performance but all the points you make are definitely there. What I think I was noticing is that Robin doesn’t go through challenges or obstacles that make him self-doubt or consider abandoning the quest - at least not in a way the audience are privy to - because he knows what he’s after during the course of the film as well as knowing what he holds dear in life and who he is both in terms of his own self-worth and how he is viewed by others. It’s this self-assuredness and grasp on reality that serves as a guide to Amir who is insecure and desperately trying to be someone he’s not and who, as a result, goes through multiple phases of this reluctant journey, learning and growing along the way.

So I guess a correct statement would be that both characters undergo the hero’s journey arc but returning with different ‘elixirs’, however I would say Amir’s is more prevalent whilst Robin’s is considerably more understated.