Browns look like an emotionally volatile team to me. We all know about Beckham's outbursts when he doesn't get the ball, and Landry isn't shy with his emotions either. Mayfield seems like a lightning rod as well.
They need to get off to a fast start and ride the momentum. If they start out bad and the pressure mounts, which it will with the increased expectations, how will they react with a rookie head coach, and a 2nd year QB?
There are also 3 other teams nobody is talking about, including the old Browns in Baltimore. Steelers might be dangerous if they quit worrying about ex teammates and the Bengals have some talent so I'm not ready to put them directly in the playoffs at this point.