I can't think of one. And if I could, I probably would be in some front office crushing player development against the odds. You're right that the more players you get, the more talent you keep, the better chance you have of unearthing great talent. The Cardinals have an approach to player development that many, many teams either have or have attempted to copy. And that is: Get as much known talent as possible, complementary talent, talent that can with development help a big-league club, and then hope that some of them break through as elite talents.
See: DeJong, Paul.
The Cardinals drafted an Illinois State hitter who had great "bat speed" -- as judged by exit velocity -- and power potential and played all over the field. They did not know he could be a big-league shortstop. Nope. They didn't until they tried, out of duress. And here he is. The Cardinals drafted him thinking he had the traits of a strong player and with development would reach the majors -- either as a utility fielder, third baseman, something, something to contribute. And because they played the odds and gave him a chance, voila, he's an impact player. I don't have a number to capture that, sorry. I doubt anyone does.
But playing the numbers definitely gives them a better chance. They do it well with pitchers. They did it well in DeJong's case. They did on Pham, and then traded him. And now they'll see how they do with the current collection of outfielders. Carlson appears to be the real deal. Does another elite contributor surface too?