CN, that's part of what the scriptures cover, in that the Lord is the One who knows. Traceability through generations that had forgotten their roots renders earthly tracing virtually impossible. What makes the difference in what I have traced is the heritage of faith through my family line going back into Ireland and Germany. That's why we are a valley of dead bones yet to be brought back to life. The scriptures he covers in those videos give no indication as to the individual tribes being able to identify, but that they are descended from Ephraim. THAT is the upheld distinction that we are able to see here, with the Lord knowing the finer details of tribal descent.
MM
However............back to the thread.....is belief in the Virgin Birth an essential to salvation.