“Poppycock! [II Kings 17:7] Therefore the LORD was very angry with Israel, and removed them out of his sight: there was none left but the tribe of Judah only.”
Not “Poppycock.” There were no tribes left but Judah only.
That there was a remnant of individuals and families used by the Assyrians in the land would not negate that.
Quite right — the other tribes were absorbed into Judea, creating ONE tribe