Obito would still either use his rinnegan to revive madara then madara would just use mazou and take Naruto and bee, or I mean obito could just prepare the juubi by himself and judging by his words he was going to initiate IT immediately, madara was the reason the juubi battle was prolonged. Also if kabuto didn't help obito then itachi would've never came and sasuke would still be hell bent on destroying the leaf, gaara wouldn't have gold sand from his father, and the five kage would have no reason to come to battle until juubito comes and only if juubito comes, also no itachi would be equivalent to no orochimaru which equals no four kages which means, juubito the coolest guy solos Narutoverse
Naruto would still have KA so the moment he looks into Itachi's eyes which Sasuke got, he would be KA with the order "Protect Konoha". Obito never planned on reviving Madara, that was Madara plan but Obito never wanted to do that and doing so would kill him. The 5 Kages, Kakashi, Gai, and the whole alliance would be there and in a much better health than they were in the manga since they wouldn't have to fight Edo's. Shikaku would be alive to give everyone strategies such as the one he gave them to block Obito's, Edo Madara, and the Juubi's sight and ability to sense them as they attack.
Obito being the last person alive (all Zetsu would be dead) would be a reason for the Kages to enter the fight, they would go to protect Naruto and Bee; all alliance members were asked to go there when they could. Also Suigetsu and Juugo would still have the scroll on how to revive the 4 Hokages and still would track Sasuke down so it really depends on if Sasuke was KA before or after. Even if Sasuke was still evil, Hashirama wasn't held down by Orochimaru's control even with Hashirama cells boosting his power so worst case Hashirama kills the summoner and head to battle with the other Hokages. If Sasuke was evil then I see him using villagers as sacrifices and use genjutsus on a ninja to cut their stomach open to free the Hokage's souls. If Sasuke was KA the he would give it to the Kages who would figure out how to do it with Tsunade cutting her own stomach and using her Yin seal to heal.
Obito achieves SO6P power on his own tho
He needed gold and silver bros to be revived to use them as the Kyuubi substitute. Edo Madara also took down the 5 Kages who could join Naruto and Bee when they first meet up with Obito. Wouldn't be hard to kill Obito when Kakashi use Kamui to let dust release hit Obito or any other attack like lava or boiling release. Naruto wouldn't be a prefect Jin at the time though unless Obito uses the Bijuus to fight but BM Naruto can take them out.
