Interesting idea, and I'd love to see a MLB manager try it, but I doubt anyone ever will. Well, maybe a manager with a bad team in a small market with three okay starters and not much else in the way of arms...no, not even then, ha ha.
I recall James discussing the use of closers years ago. The gist was that the way managers use their best relief pitcher (i.e., almost always for 9th inning save situations) was inefficient -- a lot of games are decided much earlier, say with the bases loaded in the 6th inning of a tie game and the starting pitcher getting tired. But who wants to "go against the book" and put his neck on the line?
On the other hand, watch what the best SIM owners do here during a live game. In the same situation as described above, if they've got Eck or Rivera or Gagne in the pen they bring them in. They don't use their second or third or fourth best reliever when the game is on the line. Why don't MLB managers manage that way? Fear of ridicule if going against the book flops -- and also the star closer wants his save stats.