Their idea of defining the power level of a deck based on its most powerful card(s) seems a bit ridiculous. Rating💝 a deck a 4 (highest power tier) simply because it has Ancient Tomb (the card used in their example) is ludicrous. In addition, how many players will (or, will want to) spend the time investigating the power level of each of their cards. That takes a lot of the fun out of it. When I build for Commander, I'm typically trying to make something fun with which to play.. I don't give a damn about power level. I learn that as I play, and, if my deck isn't performing well, I start modifying the deck to make it better. I'm not going to consult some arbitrary list to assess the power level of each and every card.