yeah.. what ever.. the impostant things that.. my guess is right.. and previously.. most people saying that it was wrong... sasuke would joint the battle but as madara alliance...
but maybe at that time my point is not concrete enough... my point at that time was.. sasuke would help naruto because:-
1) Madara and tobi sharingans techs.. can only be fought by sharingans ( considering the previous kages already dead) so the remaining uchiha alive beside them is sasuke...so sasuke has a big chance to win against madara or tobi..
2) sasuke is one of the shinobi who knows how to release edo techs.. so he could release madara edo techs.. this will leave tobi alone .. to be handled.. and kakashi might do talking jutsu... about why he killed rin...
3) at that point no one is powerful enough to vs againt madara.. most of the shinobi is out of chakra ..
anyway.. i'm glad that sasuke comes to help the battle.. would it be this is near to end of Naruto...