Actually looking at the power rankings, it really is just pure lazy journalism.
Every team is clumped exactly by it's win/loss record except for the Chefs.
There are only 3 6-7 teams, so they are together regardless of how well they are doing. The rankers apparently feel that being 6-7 in the putrid AFC West is better than being 6-7 in the mediocre NFC West.
This thing is utterly worthless except to confirm my unwillngness to spend the same time and money I spend on NFL on the college game. If you've got to trust these writers to set the rankings the sport isn't worth following. Luckily these guys end up looking like complete hacks more often than not. "worst playoff team in history, etc."