So Mason said the Constitution conflicted with common law? No doubt it does, in some aspects, which is why we have the legal doctrine that common law is automatically overridden when it comes into conflict with statute law.
It is extremely doubtful that he meant that the mere institution of a constitutional government would by itself immediately invalidate all aspects of the common law, including definitions of legal terms. If it had, all aspects of law would have had to be rewritten by stature, and they just weren’t. US law has gradually veered away from correspondence with English law as both countries pass statutes, but for a long time it was very similar.
In particular, if the Founders meant “natural born citizen” to be something different from that known to common law, the normal and natural meaning in a legal sense at the time, one would expect them to have explained it in more detail.
When legal men use a legal term in a document, one expects them to use it in the normal and standard sense, unless they explain otherwise. If they don’t, we quickly get into “definition of is” territory.
You'll not find a cite from any judge or elected figure, even up to and beyond ratification of the 14th Amendment, that agrees with your interpretation of natural-born citizenship being precisely cognate with the feudal English concept of liege. It cannot be, there is no sovereign other than the people under a constitutional republic. Vattel made this clear, and so did our Founders.
On the other hand, there are numerous cites and historical references, that support the contention that being born on the soil of citizen parents is precisely the understanding that was intended by the Framers, and this understanding was supported explicitly right up to Minor v. Happersett and beyond, a decision which occurred by the way, after ratification of the 14th Amendment.
Try to find any of the Founders, or any early Supreme Court Justices, stating that anyone born in the country is a natural-born citizen. You won't. You'll find quite a few agreeing with a combination of jus soli and jus sanguinis, however. There was a practical reason for this, that involves poorly understood or even forgotten roles that the several States played.
Citizenship, natural-born or otherwise, was determined by those several States, by a variety of means. In order to make the Executive eligible under all jurisdictions, both jus soli and jus sanguinis had to be accommodated. That's what the 14th was all about, recall, that no one born on the soil of the United States could be denied citizenship. Who do you think was doing the denying, and under what authority?