Have you heard of Retro Royale? Retro Royale is challenge where you can only use classic cards. There are no legendaries so the highest rarity is epic. And the elixir of the cards are the same as they are now. So the Musketeer is not 5 elixir, and the Giant Skeleton is not 7 elixir etc.
Look at videos down below for more information. Also the rarity of the cards are the same so the Prince is not rare, and the Mini P.E.K.K.A is not epic.
https://www.youtube.com/watch?v=Ht5rwDES1ig