This is an idea I had that I never really thought would work, but giving it a bit more thought, it might: The Konoha 12 (Naruto, Sakura, Sasuke, Shikamaru, Choji, Ino, Hinata, Kiba, Shino, Neji, Tenten, and Lee) VS The Straw Hats (Luffy, Zoro, Sanji, Nami, Usopp, Chopper, Robin, Franky, Brook, and other potential members that haven't yet joined). Naturally, this would need to wait until after both Anime's end. Also, I don't think the Straw Hats necessarily need 12 members to make this a fair fight.