You have to understand that while this is a manga with a lot of adult context, as in, a f*cked-up world where political and military factions frequently use child soldier (yeah, those guys are bred for war from birth; while you get used to it in the manga, consider the picture of a 10-year old holding an AK-47... That's real life Naruto for ya) in their scheming for achieving hegemony, both economic and military, where morals are simply a thing that gets in the way, this is still a children's story.
Where you have Madara (anti-villain ftw) and his Eye of the Moon plan, Danzou and his amoral political scheming, Orochimaru and Kabutou the mand scientist nerds who get uber-l33t powers, the Senju flipping the bird at the Uchiha because it's better for the Senju, and all other instances of real-world-like depictions of life...
...you also have this ninja clad in orange way-over-the-top attire, who constantly goes about this "chikara" and intends on becoming the strongest for the sake of being recognized by the village. The fact that he's nothing but a child-soldier tool for the village's elders goes unnoticed to him and to most of the reader base.
The Will of Faia gimmick belongs to the children's tale. It results in Tsunade loosing quite a few numbers on her waist figurine, along with the waist itself, when faced with reality. It also relates to the frequent shounen anime theme of "if you try hard enough, even at the cost of your life (convenient how they teach men to sacrifice themselves for the "greater" good), you will succeed", which won't stand up to reality, where no matter how driven, a person still gets beaten to half her former self (lol) when faced with sufficient firepower.
Reality stands at the bissecting role. This is Kishi's way of being modestly mature, I assume.
