While I agree with you, it's still a risky move. His numbers are great 11 k/9 and 2 BB/9 the last 2 years puts him in elite company and he's one of the league leaders in swinging strikes in the entire majors.
It's the injury history that's a big red flag. Kluber is 2 years older and has a lot more mileage on him. I understand that he'd cost more, but my point is that if you're going to abandon the "don't give up Championships for a championship" mentality that cashman said he has, to me, Kluber or Bumgarner would have been the guy to get.
However, the Red Sox could lose Porcello and Eovaldi and the Yankees adding Paxton could put them over the top, especially if they add Corbin.