yes it would make the idea of character customization as well as a more open ended story line and even multi-player!
So basicly you would start the game and you would see multilayer and single player. You could use a team given to you if you choose multiplayer or you could use the pokemon you caught in single player. IN single player you could customize you character and there would be a main story line with a ton of optional quests like in Skyrim. In multiplayer you could battle in tournaments or do quests with friends this would all be done in the same world but optimized for multiplayer.