How do the diamondbacks build solid rotations?

The dbacks are well known for creating solid starting pitching staffs due to a solid scouting department and a great general manager in Mike Hazen. Through the years we have seen elite pitchers sign here including, but not limited to; Zack Greinke, Corbin Burnes, Madison Bumgarner. Yes, Madison Bumgarner was stuck in his ways but we are still talking about a multi-world(3) champion here. But then you see the dbacks add solid pieces like Merrill Kelly who came over here from the KBO, Eduardo Rodriguez who has had injury problems but when he's on he can be unhittable. But what about Brandon Pfaadt? Well, he currently leads the league in wins with 7. If the diamondbacks can get healthy and on a roll they will be one of the best teams in baseball. And then you have the bullpen, including Justin Martinez or J-Mart, AJ Puk and Ryan thompson who both have nasty sliders and amazing fastballs that make them unhittable. Who else had a nasty fastball and slider combo? Randy Johnson. The point is, the dbacks have demonstrated year after year that they can create amazing pitching staffs and they deserve more credit than they get. Last, but not least, the impact that Brent Strom had here was insane, and the dbacks let him go because of struggles last year, I believe he was scapegoated because how else do you make that much of an impact with the Astros and then go to the Diamondbacks and turn the pitching around?