I don't know why but when I read 619, I was just thinking that Tobi knew that Madara will become the Second Hokage. To avoid this he pulled the strings to result in the fight between the two, Madara and Hashirama so that Madara had no chance of becoming the next Hokage. With him gone, Tobi would obviously succeed Hashirama as Hokage. Second, this is the reason why he supressed the Uchiha. Why would you become allies with someone you don't trust? For power of course. To make sure the Uchiha never got information on what really happened and why Madara fought Hashirama he suppressed the Uchiha to make sure they didn't find out!
What do ye think?
What do ye think?