They are very strong and their achievement is to be praised. It was not a fluke, they are still very hard to beat. It's just that they are playing Champions League as well (not to mention how big success was to pass the group stage, they are still rather 'new' to Serie A). It's they depth that's keeping them behind, it's hard to play both competitions with a limited squad and we've seen same from Viola once they went to CL.