Jets upgraded their running game to below average, maybe. They don't have any tight ends or wide receivers worth getting excited about. They will be starting a rookie QB for most of the season, I would bet. If he cannot beat out McCown, that's not good. I don't think it's a strain to say that the offense will burden the defense. The Jets have no pass rushers. Their entire linebacker corps are JAGs. Good looking secondary, but how long can they cover for? Yeah, I would call it a bad defense.
Bills defense has Shaq Lawson and Jerry Hughes at DE, better names than players. Lawson has been a disappointment, and Hughes is a former good pass rusher. They have decent DTs, but no scary pass rusher. LB is ghastly, Edmunds might lead the league in tackles. They have one good young corner in White. It's a defense that is going to be on the field a lot.
Both those teams might have just drafted a stud young QB, and if so, hey, maybe they are on their way.
I see opportunity in this division, as the Pats get older, and slower. Miami has more pieces in place than the other two teams, I think.
I wouldn't call them a good team, or a lock. If I has to pick a bad team to make a big move, I can see Miami doing it, that's all.