Jiraiya and Orochimaru, as well as Naruto and Sasuke, had their relationships turn sour slowly until they became opponents. Kakashi and Obito don't fit this mould, they both parted on strong bonds. Madara and Izuna vs Itachi and Sasuke shows the interactions between two sets of brothers. How both sets brought such destruction to Konoha and it is up to Sasuke to bascially to break that cycle of Uchiha hatred for Konoha, aided obviously by Naruto.

The Kakashi/Obtio theme seems too independent whereas the Izuna/Madara theme ties in with the fate of Naruto, the main character of the series. This fits in with the current theme of how to achieve peace in the Shinobi world where there are two options. Force, either softly via Tobi/Izuna or brute strength via Madara or Peaceful coexistance, the option fuelled by friendship and love championed by Naruto and being followed by the Kages.