Herodotus was fantastic because he was the first historian, but he is seriously lacking as a historian if you judge him by modern standards. That doesn't detract from him as a great man and an intellectual pioneer, but it does mean we should be skeptical of his theories.
For sure, everything he says should be taken with a grain of salt. I was just giving an example of a specific Greek who had some of the ideas the OP was requesting.
https://en.wikipedia.org/wiki/Herodotus#Egypt