I agree that Mayer, Rafaela and Bleis (and Casas) offer much better chances at greatness than Mata, Walter, Murphy and Crawinck, but I really like Bello, who is younger or close to the same age as Walter, Mata and Murphy. Hell, even Whitlock, Houck and Crawinck are about the same age or younger than Walter.
I feel pretty good about Bello, Whitlock and Houck, and I still think at least one from Mata (most likely), Walter, Crawford, Winkowski and Murphy will be a solid plus pitcher for us within the next 2-3 years. I'm not so confident about our down-the-road pitchers like Perales, Wikleman, E R-C and Drohan.
Team control years:
SP
5 Houck (2 pre-arb + 3 arbs)
4 Whitlock
2-3 Sale
2 Pivetta
1-2 Kluber
1 Paxton
RP
3 Schreiber (arbs)
2 Jansen
2 Martin
1-2 Rodriguez
1 Brasier
All the rest are pre-arb with 5-6 years of control.