I think the actual effect any manager has on W/L's is so freaking miniscule that the Twins would win or lose the same amount of games if it were Gardy, Connie Mack, Earl Weaver or Trey Hillman. The one thing I'd change, as mentioned above, is a nearly universal problem and that's pitching to the save rule. Use your best relievers in the highest leverage situations. It's so simple it's like telling someone not to open their doors and windows when you turn on you heat in the winter but managers just don't get it.