Just being born someplace does not equal an allegiance. We had all kinds of babies born in Germany to our troops stationed there. They had zero allegiance to Germany. They lived in US housing areas, they went to US schools, they even ate Burger King and Taco Bell and Popeyes Chicken.
Do you think they were German?
‘split allegiance at birth’ ... no interpersonal relationship between the child and the citizens of the countries is required. just the familial relationship
otherwise the term ‘natural born citizen’ would not apply
as for your example, those kids if born in the local German hospital would be US and German citizens, and that choice results in them not being natural born citizens. the point wasn’t that the kids ate chicken... but had a relationship with the other country that would open the doors for favorability... or a split allegiance.
which is the whole point