my issue is entirely that people are sold that Reinhart is going to evolve into this next tier player and sold that Hanafin won't
I think this is a mischaracterization of what the position is (at least the one I hold, and believe others do to)
It's not that Reinhart is certain to evolve further, it's that he has set a very high floor.
And It's not that Hanifin WON'T evolve, it's that he has played a lesser role, and the history of defensemen under similar conditions (looks great sheltered early) is much more fickle with regards to what that means further up the lineup. he plays a position that doesn't usually give developmental clarity at this stage.
I'm sold on two things
1. Reinhart has already set a floor. He's done it playing on a top 6 line/#1 PP... and done it out of position. Historically, you can have confidence in a forward who sets that type of floor at that age/stage. And Yes, I believe there is a ceiling that is very reachable, but the floor is already a very good young NHL top 6 forward.
2. Hanifin has already set a floor. He's done it playing protected, bottom pairing, low leverage minutes. Historically, floors set under those conditions by very young defensemen... are fickle.