Pats have had the easiest schedule, that is for sure. But teams like IND and DEN, even BUF have had easier than average schedules. There is no team, at least in the AFC, that appears to be a lock for a long run in the playoffs. I don't know that BUFF, KC, and BAL, for example have done anything to establish themselves as a top team. Neither have IND, DEN, LAC, or PIT.
There are plenty of reasons to doubt that Pats. But there are plenty of reasons to doubt all the top teams.