For not fitting Bayern, he did a pretty good job steamrolling the league for two years. Ultimately, even if there was no UCL victory, Bayern was consistent in beating teams that it should beat. Sure, he has lost against the likes of Real Madrid, Barcelona, or Atletico. He even cut it close against Juventus. Those matches are usually 50/50, and have a luck factor. What Guardiola does consistently is absolutely steamroll inferior teams, which Italian football fans are not accustomed to. Italian teams will beat a RM, but then lose against a Dynamo Kyiv.
Guardiola, I have no doubt he would still perform very well in the league, but in international competition, he would provide more CONSISTENCY in reaching later rounds.