We used to have a system that had NO starting rotation prospects. Not even guys that profiled as back end 5th starter guys. Now:
Priester
Fitts
Perales
Dobbins
Fitts
Tolle
Sandlin
Early
Valera
This isn't even counting guys with upside like Clarke, Paez, Monegro and Reyes. Definitely the best since 2015. Could argue it's the best since the Lester, Hansen, Buchholz, Bowden, Pauley, Alvarez group from 2006.