1. There might be a lot of AAAA players that are excellent defenders and better than JBJ on defense. They aren't in MLB because they can't hit.
2. JBJ had such a horrible start on offense, I wouldn't argue with a 0 WAR. A zero dWAR for this year seems puzzling, but not there are 15 CF'ers having better defensive years than JBJ. A 0 dWAR just means he has not been better so far this year. Maybe he hasn't. I haven't seen the other 29 CF'er to know if he is easily replaceable on D. Have you?