It’s not tough. The Birthers decided to try to over complicate the situation. But it’s pretty cut and dry.
Actually, the “Birthers” proffer the easiest to understand meaning of Natural Born Citizen.
When a Wigitland Citizen male and Wigitland Citizen female have a Child born within the borders of Wigitland, That Child is a Natural Born Citizen of Wigitland. How could the Child be a Citizen of any other Country at the moment of Birth???
What you describe are rules for dual Citizens. Both of my Parents were Citizens of a European Country. I was born in North America. I can file to obtain Citizenship of that European Country, as I am grandfathered, and they cash my annual fee payment. That does not change the fact I have affinity for this Country, not some Country in Europe
You do not need any man made rules, tiebreakers, minimum age to confer Citizenship, minimum years in Country, Babies born in international airways or waterways, naturalization tests, definitions of terms and words, laws of soil, laws of blood, Colonies, etc.
The thing that makes it complicated, at least when you’re looking at whether or not a person is a “natural born citizen” of multiple places is that every country can make up their own rules and they don’t have to make a damn bit of sense. Which is why it’s best to ignore them. If you want to know if somebody is an NBC American look at our rules and ignore everything else. Both qualify under those rules, done deal. Might they also qualify under some other countries’ rules? Sure. But who cares.