It’s been years since I dug into this but I remember during the Obama controversy, an earlier version of Blacks Law Dictionary spelled it out clearly. Of course they revised the definition of natural born citizen after Obama’s questionable origin story, but it was always clear as day what they meant by it. While the constitution in and of itself is brief, the larger body of Common Law is not. It clearly distinguishes the difference between natural born (2 parents, no foreign allegiances), native born (born on US soil), and naturalized (immigrated legally). There might have been one more category I’m forgetting but you get the idea - Common Law predates the US Constitution and established the meanings of the words that appear in it. It seems vague to us in the 21st century but in the 1700’s, all these legal terms were well established.