The Gra"z (commentator on the Haggadah regarding the Four Cups) brings that Maimonides (Rambam) states "yedei cheirut yatza" (freedom hands have fulfilled) instead of "yedei yayin yatza" (wine hands have fulfilled), and therefore explains it differently. He says (Chapter 7 of Chametz and Matzah, Halacha 9), these four cups must be mixed together so that the drinking is considered a mixture, everything according to the wine and the drinker's preference, etc. If one drinks these four cups from unmixed wine, they have fulfilled the obligation of the four cups, but not of freedom. If one drinks the four cups mixed together at once, they fulfill the obligation of freedom but not of the four cups. And if one drinks the majority of each cup, they have fulfilled, etc. The Gra"z elaborates to demonstrate that according to Maimonides, the essence of the obligation of the four cups is to demonstrate freedom in their drinking, they were only instituted in a specific order to fulfill a mitzvah in each one, as stated in the Gemara (Kiddushin 17b).