I don't think.so at all. Here's Rivers wins loss record the past two years under Mike McCoy, the man the Bills wanted instead of Rico.
2016. 5 and 11
2015. 4 and 12
Don't underestimate the job Lynn and his crew have done with this team. They now have more of a balanced attack with Whisenhunt calling plays, and their pass defence is arguably the best in the league now. It's alot more then just having a good QB as I have shown to you above.