There's no proof that constitutes the claims that 2 Rinnegans > 1 Rinnegan, Gedo Mazo would go to Madara, or that Kurama would go to Madara. All speculation on your part. Tobi is the one shown to control Gedo Mazo, and he's controlled Kurama as well.2 rinnegans>1 rinnegan, gedou mazou would go to madara, kurama would go with madara, cos he has hashirama's abilities and even he was able to control him, he also is senju(final version of hashirama->he has all his techs) and uchiha->also izanagi, is better genjutsu user(tsukuyomi with rinnegan).
mokuton from body and shinra tensei(maybe big one) and genjutsu would help him not to get caught by tobi, also big susanoo....no way to beat it with absorbing ninjutsu and shinra tensei meteorite and wood spam.
tobis only way is to escape, oterwise he losts by time
Tobi also has mastered Senju DNA. And he has better Genjutsu as of now (controlling a perfect Jinchuuriki > paralyzing someone) and there's no proof that Madara has Izanagi either.
Tobi can warp into Susanoo and assault Madara from there. He can hit it with 6 Bijuu Damas. Stop speculating so much and making it so one sided.