People seem to be overthinking the "perennial contender" concept. With a 14 team playoffs, the Bills are perenial contenders as long as Josh Allen is the QB, and he is healthy. You put him on any of about 24 rosters in the league and about the same number of coaches, and it would be shocking if his team didn't make the playoffs.
Similarly, you put a Derek Carr clone on the Bills with this exact same roster, and the exact same coaching staff, and no one would expect them to make the playoffs this year (Frankly, many would see them as battling to stay out of the AFC east basement with the patriots). Josh Allen having Dan Marino's career results would be horribly disappointing. Beane needs to figure out how to get Allen to the Super Bowl.