Harriet Klein argues against the assumption that Kadiweu is Guaicuruan. Most others accept the inclusion of Kadiweu into the family. The Guachi were absorbed by the Mbayá. The similarities with the Mbayá language may be due to borrowing rather than a familial relationship.Steward, Julian H. (1946), Handbook of South American Indians, Volume 1, The Marginal Tribes, Washington: Smithsonian Institution, p. 214
