Food for thought (mentions Davis who just came up in another thread, and Pivetta. Germane to the Curtis Mead discussion elsewhere too I'd think).
the Yankees have pro scouts whose jobs are specifically to roam the minors in search of pitchers.
“The Dodgers are still the best at using their scouts with analytics to recognize pitchers with pitches they think they can improve,” says one National League West general manager. “But the Yankees are right there with them. It’s obvious what the Rays have done in this scouting, recognition and developmental department, and what Boston has done with Nick Pivetta, Garrett Whitlock, Austin Davis and John Schreiber — for whom they gave up nothing — indicates where they are going.” In that final June 19 game with St. Louis, Schreiber pitched the eighth inning, striking out the side, with Paul Goldschmidt and Nolan Arenado the final two hitters. He even runs the team’s postgame win celebrations.
To be fair the Rays have tried to salvage several other Phillies relievers who didn't pan out.