Naruto isn't a Senju, but whatever, no biggie, I can see it though. It all rolls back to the sons of SO6P.
Ha! How about this, Kishi is speaking of the eternal struggle of negative and positive, yin and yang, good and evil. The key thing to realize about the yin yang is it is all about balance. If it was a struggle, then instead of a smooth line, it would be jagged and random, representing the chaos of battle. but it is not, it is the shape of two drops equally trying to overcome their counter parts position. An eternal dance of shifting counter points, a perpetual motion.
The elder representing the yin, the youngest representing yang. Positive, and negative. The tailed beasts are both, and both are needed for the creation of ninjutsu. It was as if The SO6P was a complete yin yang, perfectly balanced. Upon his death he had to devide his energy, splitting his yin and yang. Both parts, now in two seperate entities, are still in constant shifting postions, trying to over come each other.
Naruto represents the yang, in fact he only has Kurama's yang chakra. He is the positive. Sasuke is yin. He is the negative. They are both partaking in the eternal dance of shifting postions. My prediction is that they will become one, once again creating a perfect yin yang in Naruto. That is how he will bring peace, by bringing balance once again.