Great analysis, supports what I was finding.
As another wrinkle, I believeit is also possible for the Bills to get in at 8-8 with a lot of help. If NYJ-MIA-BUF end in 3-way tie, Bills win tiebreak based on 3-1 head to head vs 2-2 for NY and 1-3 for MIA. Winner of Cinn-Den gets 5 seed and need everyone else to finish 8-8 or worse. Several tie break scenarios occur which also possibly pull in Pitt and Tenn.