[Hunter]

Shadamehr I don't think I ever said that it was impossible for Naruto to learn the Rasengan if he hadn't had the Kyubi, neither I would defend the opposite btw.
It would take more time, and I don't think that he could use such a jutsu so young but yeah I don't think it's impossible, not certain either but not impossible anyway.

Then Muad'Dib, no the ninjas aren't all normal person, actually it's quite the opposite.
The Uchiha aren't normal, neither are the Hyuga, nor Haku, nor Yoroi, nor the Nara, nor the Aburame, etc.
There are normal ninja, Sakura, Iruka, Mizuki, Gai, Kurenai, Kankuro, etc.
Normal doesn't mean weak, it means without abnormal abilities.

My point it that we don't know if Naruto would have had something special on his own, an unusual and natural huge stamina like Neji or Sasuke (who has at 13 years old already about half the amount of Kakashi's chakra) for example.

And that's exactly here that you made a mistake, you think that Naruto would have a great stamina because he's the hardworker type no matter what, I will not discuss about that even if I don't really think that it's an obligation but the fact is that a great stamina, and I mean a very great stamina is about the level of Neji and Sasuke.

How many Kage Bunshin could make Neji or Sasuke while being able to fight? One or two?
To use several jutsu during the same time is incredibly exhausting, The Kage Bunshin isn't forbidden because it's a difficult jutsu to learn (it's a class C jutsu if I remember well like the Kuchiyose) but because it's a very dangerous jutsu that exhausts the chakra at an incredible rate.

The fact that Naruto is able to make 5 clones is already abnormal and I don't speak of his usual use of 50~100 clones.

EbonySeraphim and Shadamehr seem to have understand my point so I will not re-re explain what they said so just some things :

While what you're saying is generally true, stamina does not equal chakra.

That's exactly what I said, re-read my post : The chakra is obtained by mixing the component of the stamina.

People with greater chakra can have lower stamina

Once again that's what I said, a good example of that if the fight Neji vs. Naruto.
Neji's not even close to the amount of stamina of Naruto but he's a genious when it matters of chakra control and created chakra from his stamina, that's why he could fight against Naruto in a Kyubi's state almost equally.

such as when Lee commented that, though Sasuke could achieve Lee's speed, he didn't have the same stamina.

No this is wrong, Lee never say that, he said that this kind of speed used a lot of stamina, Sasuke hadn't the stamina necessary before the train of Kakashi.
And Kakashi trained him in Taijutsu exactly for this purpose, to rise his stamina.

In regards to chakra, stamina probably means the ability to replenish chakra. And in this way, the Kyubi actively replenishes Naruto's chakra through its own power.

No, once again re-read my post (or re-read the explanations in the manga).
First there is the stamina composed of physical and spiritual energy, then you must create chakra from the stamina (by mixing the two elements) and then you must use efficiently the chakra created to do a jutsu.


Oh and Crimson except that I don't think that Naruto can create 1000+ clones with ease but only when he's in a particular state of mind, I mostly agree with you about a post about Naruto!
Craaaaaaazy!