Shields would be a great add to the rotation. I'd prefer to have Sanchez/Norris start in AAA as depth who, if dominating, can come into the bullpen in the 2nd half if they aren't already up as an injury replacement. Dickey/Stroman/Shields/MB/Hutch is the best rotation in the division.
I'm confident that AA will throw enough poo (waiver pickups, Delebar, etc.) at the bullpen that something will stick and be good enough.