You’re comment about not assuming a correlation of language and genetics is spot on for this topic. In the linked article (or maybe it was another article on this topic) they mention that genetic research shows that Etruscans shared much of the same step-derived ancestry as the Latin speaking Italians. It appears that, when then step invaders came in, at least one group of them picked up a local non-IE language even while their genetics overcame the original speakers.