bWAR values Turang the most because DRS is outlier positive on Turang. It's the one defensive metric that loves him and I believe that baseball reference uses DRS to factor in dWAR.
If you go by fWAR/600 PA and fWAR/60 IP for Uribe, I think it better illustrates how valuable each of them were.
1. Perkins - 4.3 fWAR/600 PA
2. Frelick - 3.8 fWAR/600 PA
3. Wiemer - 1.6 fWAR/600 PA
4. Uribe - 1.2 fWAR/60 IP
5. Monasterio - 0.8 fWAR/600 PA
6. Turang - 0.3 fWAR/600 PA
Even bWAR this makes it look more clear.
1. Perkins - 4.3 bWAR/600 PA
2. Frelick - 3.2 bWAR/600 PA
3. Monasterio - 2.5 bWAR/600 PA
4. Turang - 2.1 bWAR/600 PA
5. Uribe - 2.0 bWAR/60 IP
6. Wiemer - 1.3 bWAR/600 PA
One thing is very clear. Blake Perkins was very underrated by the voters. On a per game basis he was the best rookie. Really just a combo of competent hitting (88 wRC+), great baserunning, and great defense is how he got there.