The only reason this might happen is because Luffy seems to be out (for now) but if he recovers I doubt it will be anything close to Madara.
Besides you're confusing Saturn with Im, if this was Im I might be inclined to agree, but Saturn is one of five Gorosei so I doubt it will be anything close to Madara's showing. Plus, Zoro is messing around with Lucci and Saturn has a ton of Pacifista and marines to back him up. If he does get a dominant showing there will be a ton of insinuating circumstances here.
At the moment it seems the strongest person to face him will be Jinbei, and that doesn't bode well for the straw hats.