See?? Even those advanced civilization aliens couldn’t get their circles concentric!
That is the fault of me, the image chooser. There were a lot of astonishingly symmetrical crop circles shown, but many seemed to be drone images from directly overhead that made it hard to tell they were actually cut into crop fields.
I have no position on the matter whether such large images are alien-generated or not; but whomever did them, many are amazingly precise. Example (those little dots are people walking around in it):