Note that while Lehi speaks of a scattering and a gathering, he includes all of the house of Israel in that context. Lehi does not specifically mention the ten tribes. We have no mention of the lost tribes until Nephi's exposition in 1 Nephi 22:4.
For those who would proclaim that the Book of Mormon took traditions of the lost tribes mirrored the popular opinion that they were the American Indians, the Book of Mormon itself is specific in its denial that the American Indians are at all associated with the lost tribes. In the Book of Mormon the lost tribes are lost somewhere else. The Lehite band does not consider themselves part of the lost tribes, and when spoken of, those tribes are consistently spoken of as lost somewhere else. It would be remarkable for Joseph Smith to attempt to adopt a popular idea as support for his new Book, but specifically deny that connection in the text thereof.