The Belichick system wasnt successful in Cleveland and hasnt been successful in New England without Tom Brady. Even with the highly touted Drew Bledsoe as QB, the Belichick system was not successful. Meanwhile, Tom Brady left New England and promptly won the SB in Tampa. Even when the evidence hits you in the face, you still refuse to see it. Which is a revelation of your mental aptitude.
Coaches are only as good as their players. Their greatest talent is identifying elite talent, which Belichick did by sticking with Brady even when Bledsoe was healthy. The great Alex Ferguson at Manchester United was mediocre until he signed Eric Cantona. Then he went on to cement his legacy by signing David Beckham, Paul Scholes, Ryan Giggs, etc. Phil Jackson had Shaq and Kobe at the Lakers and Michael Jordan and Scottie Pippen at the Bulls. His triangle would never have succeeded without those elite players