True, I played in the Cup against a manager of level 8, but level of the club was 4, and my club was level 3.
just see his information, now one manager of level 22 can leave the club and start with another at level 1...
so now we have 3 things...

nº of seasons, 22 in my case
manager level, 15 in my case,
club level, 15 in my case but if I take over a club of Level 1, will be level 1.