A manager with higher manager level has no advantage except for experience. The difference in management levels cannot indicate the difference in experience because this difference shrink as teams promoting after taking over. For example, I am a level 17 manager managing a level 17 team. But I was a level 8 manager handling a level 1 team when taking over it.
If you are confused by the manager level, I suggest you ignore it and the tiny number on the photo of the manager.
In contrast, club level really affects the strength and potential of a team.