The way they relate is by their different character traits and how they deal with things throughout the template. In the ordinary world part, they both know nothing about the other side. The alchemist in it did not know about the soul of the world and some other things, and Harry Potter did not originally know about magic. Next would be the call to adventure. I noticed that this was very subtle in both, as they were both hesitant at first but decided to go with their adventure after they both met their mentors, both very old, wise guys, where one was the headmaster and the other a king. After crossing the threshold, there was not one for Harry Potter, so we move on next to tests, allies, and enemies. They both meet some allies and have to face some problems along the way, and they also make some enemies on their journey. After the ordeal, they both have to deal with a great power. Harry had to deal with one person, but Santiago had to deal with a bunch of men, a little different. The reward is where they get their treasure; their reward is basically the same, but Santiago does get some physical treasure, whereas Harry only gets wisdom. The road back was pretty much the same as they both returned home for resurrection; it would be all the info and character growth they went through. Lastly, the exile would be when they are back at their homes; there isn't much of one for Harry Potter.