Anime logic =/= game logic.
In the game the stats determine everything, but the anime is more dependent on backstory & a Pokemon's own capabilities. E.g. what Ash's Pikachu is capable of far exceeds what any Pikachu can do in game (since it's such a frail Pokemon species), and the same thing applies to Mew & Mewtwo.
In the anime, Mew is the original Pokemon, and all Pokemon DNA can be traced back it, making it the beginning of Pokemon life (after Arceus the creator Pokemon, if you go by the legend that it created the Pokemon world). It can learn nearly all moves available, and is a highly intelligent Pokemon. Mewtwo is a clone of Mew, and while it's at first seen as 'stronger' than Mew, it realises that its actions were wrong from Mew's help.
I guess if you really wanted to to equate anime & game stats, Mewtwo is the Pokemon that has power whereas Mew is the Pokemon that has wisdom.
