Bottom line here. Look at the Steelers , and the patriots. Yes , they do make the occasional big free agent deal , but for the most part they are built through the draft and run by top personnel men.
The Bills deterioration has nothing to do with changes in the amount of divisions or changes with the playoff system , but the stupid hires , free agent signings , and most importantly the horrendous draft choices over the last decade are what caused the Bills to be perennial bottom dwellers....that and the Flutie curse.