WAR isn't perfect. Maybe you saw bWAR in this time, but Buehler's 2 year average fWAR is 4.05, and Kershaw's 3 year average is 3.67. (2 year = 3.35)
I don't know how bWAR underrated Buehler's 2019 season, but I cannot agree with 182.1 IP 3.26 ERA 215 K becomes 2.2 bWAR.
Basically idea was great. There's only one problem in showdown I think - DIFFICULTY : ROOKIE > ALL-STAR? no way
I give it up quickly and playing US conquest now. If there's no patch I don't think I'll play showdown again.
Didn't try Granderson mission, but Eckersley mission is working now so I think it'll be work