I believe that both of these languages are dead, are they not? If so, how do we know what they sounded like?
Etruscan isn't spoken (other than some loanword descendants) and longer texts of the language are nearly unknown. There are some Latin-Etruscan bilinguals, and some "pidgin" inscriptions; also the Lemnian stele, which was found on Lemnos in the Aegean (!) and appears to record Etruscan or something like it (or ancestral to it). The ancient sources say that the Etruscans were transplants to Italy, having come from the Aegean and Anatolia. That remains my view.
The way to pronounce Etruscan is a modern guess, based on the bilinguals, plus some comments in surviving ancient sources. It would be nice if Claudius' history of the Etruscans turns up in the Piso library in Herculanaeum, or anywhere really, regardless of how much chaff may be in it.
Polynesian is still spoken. Greek is still spoken. :')