Yankees’ deep pool of pitching prospects the envy of the league

It’s not the top-of-the-line prospects where the Yankees’ system separates itself from the other 29 systems in baseball. It’s the fact that the line of prospects never ends. A prospect base that’s led by Justus Sheffield, Estevan Florial and Clint Frazier is backed by a seemingly never-ending supply of pitching, a collection of arms that…