No, your point is this, specifically: "looking at who's been selected at #1 is not as relevant as looking at who's been selected at #1 and below."
Which is a massive logical fallacy. You're arguing that one must not look at who was chosen as a first pick but who could've been chosen. In hindsight, of course. And with the exception of the Kenyon draft and maybe one other, you can find a very good to a great player in every draft. The problem with this logic is that it not only looks at things in hindsight, but that it ignores that if other teams do not draft optimally, there's no reason to believe that the Jazz will.
In other words, the probability of the Jazz would pick a Hall of Famer with a number one pick cannot be exactly calculated do to many variables, but surely, the relevant numbers to crunch would be how many #1 picks lead their teams to a title. Not how many number one picks could've led their teams to a title, had they only picked the right player.