It takes a team to win. QB is obviously the most important position and having a great one gives you a leg up but some people act like its the only position. Even a great QB isn't going to win with a bad defense and the most important positions on defense are on the line.
At the end of the day, everyone plays with the same budget. The team that wins is the one that is the healthiest and gets the most value for its money. A team should really build itself based on investing in the positions where there is a scarcity of talent.
Scarce talent (ie. less good ones than slots available): QB, LT, DT, CB
Non scarce talent (more good ones than slots available): RB, TE, 4-3 LB
Personally, I think one of Jerry's biggest flaws is that he has a tendency to overinvest in positions where he could get roughly equivalent play for less money. Dalton Schultz was a pretty good example of that this year. He wasn't elite but he was perfectly fine. A great team needs bargains like that.