I have used the tandem rotation for the #4 SP, but I think Starter 4A/4B would be a logical improvement. I could alternate 2 low IP SPs in the #4 spot in a 4-man pitching rotation and set the TPC/MPC high, instead of using them as SP/RP with low TPC/MPC. The net results would be the same, but the SP rarely pitches enough innings to get the win in the tandem setup.