Bills need a better o line, wr, 2nd rb, and an edge rusher. With the right moves this off-season they could be in the SB mix next year. They have money to spend and should get some immediate veteran help while players develop and Allen is on a rookie contract. With a better line and more weapons Allen might really turn a corner next year.
They also need an athletic tight end who can block and catch the ball. Hopefully Knox can become that guy but dropping 20% of your targets (2nd most in the league) is absolutely terrible.