I was level 2 and faced a level 23 team in the cup, lost with 7-0 and 6-0. It wasn't that bad, thought I would loose with 15-0 both matches.
Faced the same team as a level 3 manager, then he was 24 and I only lost with 3-0 the first leg and 5-0 the second leg, hard defensive and hard tackling was my way to deal with him, I did injure his ST at the first leg.