I think somewhat the opposite, it's very hard to assess the criteria of his management because even under Naglesman from my perspective watching that Bayern team they didn't perform to the same level as they did with Flick.
Flick's time at Bayern saw them do a multitude of things well, they pressed high, was good in the transition and had good technical proficiency among their players to open up spaces. It was for me the most complete team I've seen in Europe for a good few seasons. But it's hard to pinpoint if that is solely on him or also a favourable mixture of timing and a good set of players to build things with.
The only way we'll know for certain is if he does it at another club. I also don't really account international football as being relevant with domestic, totally different aspects revolved around management. I think the Bayern fans would have a better insight because as it stands if he is to be given credit for coaching that team, we're talking about a very high level that would outmatch Klopp / Guardiola (at the time).
