Natural born citizen is a unitary phrase, no part of it can be omitted without changing the fundamental meaning of the phrase.
A natural born subject is in no way similar to a natural born citizen.
A citizen is not a subject.
What is “natural” for a monarch and his subjects is antithetical for a republic and its citizens.
“Natural born” is not a simple adjectival phrase, like “big red”.
A big red ball is fundamentally the same thing as a red ball, a big ball, or a ball.
A natural born citizen is fundamentally different than a natural citizen, a born citizen, or citizen: omitting any part changes the fundamental meaning of the whole.
You believe that a “born citizen” and a “natural born citizen” are the same, that “natural” is superfluous. As we saw with the big red ball, if one part can be omitted then any part can be omitted. Yet that rule can not be applied here unless we accept that a natural citizen, a born citizen, and a citizen, are fundamentally the same. Do you accept that a born citizen and a citizen are the same, even though a citizen may be naturalized? In your view a naturalized citizen is not eligible for the Presidency while a born citizen is, so a born citizen and a citizen are not the same.
It is apparent that no part of the phrase can be omitted without changing the fundamental meaning of the phrase.
No, it isn't.
And "natural born citizen" and "natural born subject" are KNOWN to have been used in an absolutely synonymous way in the early United States.
You have no word of any Founder, Framer, or any real legal authority in history to back up that claim. It's BS.