Randomized oversized commander, draft the rest. Since there are 5 commanders, possible decks occur meaning its easier to build the cube around those 5 decks. Easily 10 commanders.
This cube will be smaller than normal, for financial reasons. So draft Commander decks in this will only be 50 card minimums.
Commanders: Ertai, the Corrupted, Jeleva, Nephalia's Scourge, Hazezon Tamar, Derevi, Empyrial Tactician, Kresh the Bloodbraided
Extended commanders: Alesha, Who Smiles at Death, Riku of Two Reflections, Anafenza, the Foremost, Narset, Enlightened Master, Damia, Sage of Stone