Egyptian and Greek Influence on Jewish Religion

I finished The Cambridge History of Judaism, Volume Three: The Early Roman Period. I particularly liked J. Gwyn Griffiths' essay, "The legacy of Egypt in Judaism". Griffiths asks: Why should we assume that Jews absorbed such ideas as post-mortem judgment and messianism from the Zoroastrians in Persia, when they could have gotten them from Egypt, for Egypt had a belief in post-mortem judgment as well as talked about deliverers in the last days? Griffiths does not think that the Jews absorbed the notion of eternal torment from Egypt, however, for the Egyptians were essentially annihilationist regarding the fate of the wicked. Griffiths posits that the Jews got eternal torment from the Greeks, "since an early Greek tradition presents Tityus, Tantalus and Sisyphus as sinners who are tormented ceaselessly" (page 1049).