His success has obviously been helped by Brady, no doubt about it. Is it lucky to hit on a 6th round QB? Absolutely. Is it luck to develop that player and maximise his strengths? Not one bit,
If anyone has read the book War Room by Michael Holley, you'll see that Belichick is simply reaping the rewards for a lot of trial and error. His greatness comes from being his own biggest critic. He stays true to his process and brings people on board that are willing to buy into that. Everyone from his coordinators to the equipment guys are Belichick guys.
I've dug into Bill and his career quite a bit and I'm something of a Belichick disciple. If he's willing to take me on, I'm ready.