The Old Phrygian corpus is short and largely dedicatory, and the Greek and Roman writers who describe the cult of the Mother report its rites and the story of Attis without any account of origins. It is not that two readings compete; it is that the material has never yielded one, and the question has effectively been set down rather than argued over.
What would resolve this A longer Old or New Phrygian text of narrative character, or a securely Phrygian iconographic sequence depicting origins, from the highland monuments or a sanctuary excavation.
OpenAnatolian epigraphy and Phrygian philology, with the archaeology of the Phrygian highlandsMircea Eliade (ed.); Lindsay Jones (ed., 2nd ed.), Encyclopedia of Religion