Would Rubio qualify as a natural born subject in the colonies?
Yep.
Does that mean he qualifies as a natural born citizen in the USA?
Yep.
Easy.
If you can read. The former colonies knew what they were voting on. And the Founders knew what they were writing when they added that phrase.
Subjects are not in any way related to citizens.
Subjects are the chattel of the sovereign, by virtue of the location of their birth, while citizens are themselves sovereign, not the posession of any other. Citizenship is alien to English Common Law; it has no understanding thereof.
Save your childish deceptive rationalizations for your irrational friends.
Simplistic claptrap...
JC