One Piece is currently in the Elbaf arc, and it is here that Oda is finally setting up a big confrontation between Luffy and Imu. One Piece fans have been waiting for this battle for years now ...

The Straw Hats would most likely hinder Luffy at Marineford due to the chaotic war nature. Even if they took out smaller Navy units, the Straw Hats wouldn't change the outcome at Marineford.