On my reading Aristotle did not think that the Greek gods were an explanation for the existence of things. He saw a need for an uncaused cause, which he called the the unmoved movers or a single unmoved mover--even though he thought the natural world was infinite into the past. But this was an entirely different concept to him than the greek gods, who were reputably powerful beings but were contigent on causes external to themselves like the rest of nature.
Sorry...meant to point out also that I am not sure Plato talked much about it, but I could be wrong. I have not read all of Plato’s works. The one really delving into metaphysics seemed to be Arostotle as far as I can tell.