Was Lendl a transitional champ? He couldn't win slams until McEnroe was past his prime, Connors was old, and Borg was retired. Perhaps you could make the same case for Murray gaining from OldFed, retired KneeDal, and Djokovic past his peak. Lendl basically physically outlasted his competition and though I like Edberg, Becker, and Wilander they were a far cry from the all time greats before them.
Not to say Mugray will have a career anywhere near Lendl, but maybe he'll win a few more slams if he get to play competiton like Mecir and Perfnors in slam finals