Naruto Shippuuden Episode 334

[Kraco]

As they just established in this episode, Nature chakra is not, like, this weird thing you need to know how to use. Sage mode lets you collect it, but once you have it, you can do all the same stuff with it that you do with normal chakra.

After all, the Cursed Seal is Nature chakra, and Sasuke could use it just fine without knowing a damn thing about Sage jutsu.

Edo Tensei could function the same way. The jutsu itself draws in the Nature chakra, and the zombies just use it the way they would any other chakra.

Again: If it was so easy and convenient, everybody and their ninja dogs would be using it. But it isn't. You need to be a sage or have it in your bloodline. That's why incredibly few people have used it and Kabuto seemed to be beside himself that he's able to. The cursed seal apparently, maybe, allowed it, but it seems to me like it wasn't any shortcut to happiness. It was more like a part of Orochimaru himself parasitically inside the curse marked people, and that allowed the nature chakra to flow into them.

They haven't shown a single advantage a living human has over a Reanimation. The only real downside is being under control of the user, but I suspect that if the user wanted to, he could let an reanimation be completely under it's own control.

Dunno. I have a feeling those zombies can't get it up anymore. Maybe it would be a viable option if you were already an old geezer with grandchildren, but before that, not worth it just for the power and undead immortality.