1.it dasint make any sense 1.Obito operated in secret, only using Madara's name during his private meetings with Nagato, the figurehead he uses to lead the criminal-organization, Akatsuki.
2.Although Nagato believes that Obito really is Madara, the actual Madara also has some knowledge of Nagato's existence and abilities. Likewise, Obito has claimed that he encouraged Yahiko to form Akatsuki and that he "gave" the Rinnegan to Nagato.
3.Both events occurred before Obito's supposed death, further complicating the truth of Obito's history.2Before he starts publicly operating as Madara, Obito uses the name "Tobi" during his interactions with others. He wears a swirl-pattern mask that focuses around his right eye: a Sharingan, the counterpart to the Sharingan he gave to Kakashi. Obito has been able to evolve this Sharingan into a Mangekyō Sharingan. Although his mask covers the left-half of his face, it is later revealed that he has a second Sharingan in his left eye. He has many other Sharingan in storage.
4.Also in his possession is a sample of Hashirama Senju's DNA - acquired around the time of Madara's supposed death - which he uses to make copies of Zetsu. Zetsu knows that Obito is not Madara and persists in referring to him as Tobi.
5.3Obito's actions over the following years are largely unknown. He at some point became intimately familiar with the history of Madara Uchiha, an early Uchiha who helped create Konoha and had the power to control the Nine-Tailed Demon Fox.
He also began to share Madara's ideas and beliefs: an animosity towards Konoha and its Senju clan; a special interest in the Nine-Tails and other tailed beasts; the Eye of the Moon Plan.
Although Madara is believed to have died shortly after the founding of Konoha - an event that took place decades before Obito's birth - he is aware of Obito and his goals.The nature of their relationship is unclear.So its cant be obito or many things of this story haw plotholes,ant bad timelines.