I would point out that the purpose of the 14th amendment was to grant citizenship to slaves, not re-write the rules for Article II eligibility. If you are arguing that the 14th amendment definition meaning of "subject to the jurisdiction thereof" is consistent with the founders original intent and understanding, then I am open to proof regarding that, but if you are suggesting that it redefines Article II, then I have to disagree.
Article II was never defined. The Founders deliberately left a lot of the language vague as a compromise to strict language. Where the definition is not given and is subject to interpretation, then the intent of the founders must be discerned based upon the circumstances at the time of the drafting. Further while the 14th Amendment did not affirmatively change the definition of Article II, it did affirmatively define it, something that wasn't done in 1789. Therefore we have to assume that the definition of a citizen at birth (which is the definition that Vattel was defining in his treatise) is the same definition for a Natural Born Citizen. It is and always has been the definition of a person who is considered by the law to be a citizen by virtue of their birth and a person who does not have citizenship elsewhere at the time of birth.
One can only be a Natural Born Citizen of one country. That was the whole idea behind Vattel's thesis. Vattel defined what was a Natural Born Citizen in accordance with the Laws of Nations existing in the 18th Century. The 14th Amendment defines the term in accordance with the Constitution as amended in the 19th Century.
Since the Founders did not specify a definition in perpetuity, the amendment to the Constitution effectively defined it constitutionally for the first time. Hence anyone who fits within the definition of a Citizen at the time of birth under the 14th Amendment is, by virtue of that Amendment, a Natural Born Citizen. This is not in contradiction to the intent of the framers.
The framers allowed for amendments to be put in to change the constitution or to redefine such ambiguous terms as Natural Born Citizen. The whole premise of Natural Born Citizen was to prevent dual loyalty. So if a person is born a Citizen of another country, they cannot be a Natural Born Citizen of the United States. The intent of the framers remains intact even though the definition of what is a Natural Born Citizen has been given a more specific definition than was placed into the constitution.
Under the 18th Century definition slaves were not Natural Born Citizens, but were "subjects". Under the 19th Century definition slaves were born subjects and hence were now considered Natural Born Citizens. It was a paradigm shift of sorts, but the intention of the framers remains intact.
Dual Citizenship at the time of birth precludes Natural Born Citizenship Status. That was the intent of the founders and that was not changed under the 14th Amendment.