Why was the Shinobi War started if
Kyuubi chakra was all that was needed? Without Naruto (Kyuubi) and Killer B (Hachibi) being captured, the eternal genjutsu (Moon Eye) was initiated by Tobi/Madara. The reason being they could do it, is because they had one of Hachibi's tentacles (courtesy: Sasuke) and Kyuubi's chakra (Gold and Silver brothers). So which means all they needed was a sample of Kyuubi chakra (since all 7 Tailed Beasts were sealed, it was powerful enough to begin Moon Eye, also they had Hachibi's tentacle). Why did Tobi initiate the war if he could have collected Kyuubi chakra somehow? If Tobi knew about it earlier, could the war have been avoided?
His ambition could have been achieved without any war.