the ever-popular Gudea of Lagash, from about 1200 years before this image of Suppiluliuma:
Wow. The archaeologists have been busy collecting his images.
For me I imagen many of the similarities are do to the materials and the limitation of the tools they are working with. Sculpture takes a lot of finesse to get it close to what your trying to depict. Plus trying to do a monolithic sculpture is going to show a lot of errors so it is going to take a lot more work and a lot longer.
Or if it is ancient aliens then they just beam it down and charge the locals in gold per copy.
Has Gudea ever been to Google ?