There are 2 ways you can exploit the new Cup system they have applied this Season.
1.)
If you're a high level Manager make sure you buy new players at the begin of the new Season (not at the end) to push your Quality to max when Cup matches are ALREADY made. It will stick you in a group with managers on your Quality before you buy/bought the new players.
2.)
You fill up your Bench and Sub with young and cheap 3* Players and keep them till they age out. After 2 Seasons they will be 1* Players but make sure to keep them. You'll downgrade your Overall Quality with that players to have high chances to win the Cup