It's impossible to win the Cup. I've won 9 consecutive leagues out of 10 seasons, been in every CL semi and won it 3 times but never passed the 3rd round of the Cup. The Cup has to be divided into levels as well. The lowest opponent should not face a team more than 3 pr 4 levels above.
Once I beat a team from a lower level 18-0!!! How realistic is that? Not to say how uninteresting it could be as well.