"Considered as" does not mean "is." An adopted child may be "considered as" a family member, but they are not actually related.
“Is,” “as,” that’s just parsing of 19th century grammatical expression. The bottom line is “NATURAL BORN CITIZENS.”
What I think we can all agree on is that what it doesn’t say is: “the children of citizens of the United States that may be born beyond Sea, or out of the limits of the United States, shall NOT be considered as natural born Citizens.”