I think it’s easy to prove Belichick’s superiority, and in a very quantifiable way. Check his fingers.
But as for the intangible/faith qualities, it’s not about existence. Sure they exist. It’s about acceptance and complacency. When the team thinks “well this worked last year,” they’re ignoring that it worked in a different league. Other teams around, particularly the closer ones, will improve. And what worked when those were lesser teams might not work so well when they’re better ones. Especially since this process involves evaluating one small part of a very large machine.
Sure, there is the adage “if it isn’t broken, don’t fix it.” But just because it isn’t broken doesn’t mean it’s optimized...