Football is a curious sport. Your coaches suck, the OL sucks, when your QB sucks. Conversely, your coaches look great, and so does your OL, when your QB is great.
I'm going to say something blasphemous on here: Scarnecchia coached an OL that played in front of Brady. They were bringing guys in off the scrapheap. Compton, Jennings, Donald Thomas, finding guys in the 7th round, Koppen, off the street, Connolly, Neal, etc. He was either the greatest OL in history or he coached an OL in front of a guy that got rid of the ball in 2 seconds.