I remember [from Greek Mythology in HS in 1982] that Greek heros were born out of relations from the mythological gods and humans. There is a parallel between these 'men of renown' and Greek heros [Hercules, Archilles, Odysseus, Perseus, Jason, etc].
By believing in the scriptures, I would have to say that my personal belief is that the Greek heros were actually the offspring of the fallen angels and the Nephilim. Of course that could be subject to change as I am enlighten by the studious and scholarly members of JWnet.
sincerely,
dc