The Etruscan language is read only in short, largely formulaic texts, and the longest survivals, the Zagreb mummy wrappings and the Capua tile, are ritual calendars rather than narrative. What Roman writers preserved of the Etrusca disciplina is the part that interested them, the reading of lightning and livers, and it does not include a cosmogony. Nobody holds a position on what the Etruscan account was, because there is nothing to hold a position about.
What would resolve this A long Etruscan narrative text would settle it. The known corpus is almost entirely epigraphic and funerary, so the realistic route is a new find of the length of the Zagreb wrappings that is narrative rather than calendrical.
OpenEtruscology, with epigraphy and the archaeology of Etruscan sanctuary sitesMircea Eliade (ed.); Lindsay Jones (ed., 2nd ed.), Encyclopedia of Religion