No team in recent years has won because they added 1 or 2 players per year in the draft until lo and behold a team wins a championship. I don't personally know the secret sauce beyond having a top QB and a top head coach. I mostly follow the AFC. In the AFC there are four organizations that seem to be able to compete almost every year, despite drafting with late picks due to their successes. These teams are the Patriots, Steelers, Ravens and Chiefs. The Chiefs have already won a super bowl with the current QB & signed the QB to a record setting extension, and still seemingly improved this year. The Bills have improved a lot compared to the prior Bills teams of the last 20 years. This year Bill's fans were hoping to see the Bills improve enough to compete with the top teams. Hopefully the 2020 Bills have improved enough to beat the 2020 Patriots, Steelers and Ravens. It is not quite enough that the 2020 Bills would likely crush the 2017 Bills.
The QB rookie contract window is closing fast. Beane's job becomes much harder once Allen rolls off the rookie contract.