His "strength" was being part of a system that developed young pitchers very well and spotted pitchers on other teams that they felt had something special, or something that could be adjusted to make them better with them. While Bloom literally "wrote the book," we don't really know if he was the talent that made it happen.
My original point is that he has seemed to hit on some hidden gems, like Pivetta, Schreiber, Whitlock, Wacha, Strahm, Hill and a few others, but that some of his "misses" have maybe, and I stress the word "maybe" been just bad timing. Of course, one wonders why they didn't or couldn't have done better while with us. Where was that "adjustment" we seem to see with the Rays, even now, after many of their top management guys have left to go to LA, HOU, BOS and elsewhere?
He missed with Richards, Perez I, Andriese, Paxton (so far), Sawamura and kind with Perez II, but he has also done pretty well on several others. The jury is still out on Seabold, Wink, German, Kelly and Wallace. (I'm probably missing others.)
I'm not sure what the success% in in TB on non-drafted pitchers.