Marduk said:
I don't buy the elephant origin for cyclops either, the Greeks were familiar with elephants, they used them in their army ...snip...
Yes, it has its holes.
However it may not be far-fetched. Ancient Greeks were people just like us. Some were bright, some were dull, many were somewhere in-between. Some were very rational, some were very gullible, most were somewhere in-between. Some knew pretty well the limits of their skills, some did not, and so on.
Now, imagine KotA's Ancient Greeces equivalent, a guy who calls himself King of the Athenians and which happens to claim to be the timely truth among other things. Its not hard to imagine such a guy could look at an elephant's skull (or to a carving or drawing or it) and claim "It must be from a monocular giant! Elephant? No way! Where are the trunk's bones?" King of the Athenians, of course, would not accept someone else's arguments.
King of the Athenians, by the way, would be exactly the kind of guy whom, after looking at engravings and/or drawings say, from a Minoic palace, would claim ordinary humans from his past could not have built such a colossal thing, since he could not figure out how to do it. Maybe, Zeus knows, King of the Athenians would claim a race of monocular giants built the Minoic palace. His next step would be to grab Polyphemus myth and distort, I mean, reinterpretate it, force-fitting it in to his beliefs, turning the two-eyed giant in to a single-eyed giant.
It could happen, just saying...