Oh that's most definitely the case. Bad drafting and the Butler debacle aside, I give Bill and Co. a lot of credit for how well they managed to get those SB winning teams to tune out the noise and for really preparing them at key junctures, and there were so many of those that could have sunk lesser coaching staffs: whether it be responding to that MNF blowout against loss the Chiefs in 2014 with a statement win against a Bengals team going in with apparent momentum, not letting the Deflategate media circus sink the Pats in SB 49, guiding them to a 3-1 record without Brady in 2016, getting the defence to turn things around in that same year following a loss to the Seahawks and the Collins trade that very same year, keeping the team composed in SB 51 even down 28-3, and getting a seemingly over the hill Pats team to respond to the doomsaying during the 18-19 playoffs by utterly dominating an on-paper more talented Chargers team in the Divisional.
Bummed as I am about Brady leaving, and for as long as I think it'll be until the Pats are SB contenders once more, I'm not gonna pretend that Bill didn't play an immense role during that 19 year long partnership.