I think he has more potential too be Madara's right arm, than Obito; as Obito has addmtted that he never wanted to be friends with Madara... So chances are clanssmen arn't all what interest Madara as he's not only been burnt by one already, and with that, Sasuke would prolly go on the offensive... that, and or Madara would rather anotger Uchiha pupile; as his current is trash to him now that Tobi doesn't wanna revive Madara fully.... unless that was a ploy too lure Naruto into thinking that Tobi can change or something... as Tobi did not plan on Kabuto revive Madara... and he did say that he was sorry that he was Edo'd and thus not being able too revive him normally...