one thing for sure...
Tobi is an old guy... and once became a Mizukage...
this is the number 1 evidence that Tobi might not be Madara
as you can see here....
Kabuto said "I would come greet you, Tobi"
If kabuto knows he's the real Madara then he would have said "I would come greet you, Madara"
and he said... "excuse me... You go by Madara this days, Dont you?"
-> isnt this supposed to be suspicious??
I think kabuto knows he is a fake Madara...