Board Thread:Wiki Discussions and Support/@comment-5407586-20141206094948/@comment-945885-20141207030150

For the way the war arc is broken up, see jo-ha-kyū, which roughly parallels the Western three-act structure of storytelling. Of course, it's ironic that the climax ("rapid") act of the Fourth Great Ninja War is only slightly shorter than the first two acts combined.

The way the databook divides the Fourth Great Ninja War arcs, the second arc ends with the defeat of the previous generation of Kage and the third begins with the revival of Madara. It makes sense, as the second arc is focused on fighting the White Zetsu / Edotensei Army, while the third arc is focused on the three-front battle against Tobi, Kabuto, and Madara.

The War arc then transitions into the Ten Tails' Jinchuriki arc, during which Obito and Madara both become Ten Tails' Jinchuriki. Makes sense.

Then the Kaguya Arc begins after Madara casts Infinite Tsukuyomi, when Kaguya is revived. Again, makese sense.