I don't agree with the proposition about the Cup would be only for the same level teams.
With that way, only the wealthy teams (token buyers/farmers) will be the top dogs of the competition.
If they know that they 'll face only teams from their level, they 'll increase much more the quality of their team and make them unbeatable in all the competitions.
Now at least there is some "brake" to that because of this Cup draw (hope and fear).
But Cup should be something unique.
I don't know how, maybe using only the "bench" players of the team ? The weaker ?