We can only talk theory, not long ago people were shitting on Flick. There are mamy variables on football as you have 20 outfield players on pitch so its hard to think about any "what if"...With his offensive football I do think they would do much better stats wise. All 3 being elite in finishing and very fast, with all the chances served - looks easy to imagine them vandalizing league teams with goals.
Nobody dragged MSN down, they won the treble and dominated league. Could have achieved much more but in theory, that's mostly their responsibility as you say but Enrique proved in 14/15 that coach can play a role too. So little doubts that Flick would keep them disciplined.