Arraez has gotta come back to Earth at some point. He's been an absolute line drive machine, but even if he is the 2nd coming of Rod Carew he can't keep hitting them at this pace. So no, I don't think he needs to stay up this year.
"Polanco leads the team in bWAR and WARP and tied with Kepler in fWAR.So it is Polanco" I lean Kepler. He has provided an extra win when one considers their WPA.