The Bills did beat the Patriots in Buffalo last year, but they lost every single one of their other divisional games.
Bringing in Mario Williams will drastically affect their defense, but most importantly, it will affect it in the right way to take advantage of the flaws of the other AFC East offenses.
Because of the strength of their pass rush with Williams in the team, the Bills would have all the tools to frustrate Tom Brady even further with their pass defense, while the New York Jets' offensive line proved itself to be a liability last year.
The Miami Dolphins may not have their quarterback settled just yet, but the right side of their offensive line remains their fatal flaw on offense right now.
Joe Philbin, as a former quarterbacks coach, is going to want to throw the ball in Miami. He, like the other AFC East teams, will probably be forced to run a lot more against the Bills.
After a 6-10 season last year, nobody is worried about the Bills winning the division. If Mario Williams signs for the Bills, then that could change pretty quickly.