In CUP is normal to face managers 1 or 2 levels higher.

In LEAGUE and CL can happen, because people have the option to change team in a lower level.

For example he was playing on level 5, but he decided to change team, and picked one from level 3. The managers keeps His level, so he still appears as a level 5 manager, but the players Will have the same quality as yours or similar to it.