One of your big assumptions is that the AE would have done the 'reasonable easy to do thing', use a counter-weight, yet they were clearly illogical. There is no rational reason to build a huge pyramid - but they did so many times. Why bury boats next to the pyramids?
Don't overplay the 'AE were reasonable' card too much as a reason they would have done something you a modern man think is a good idea or that the science shows would be the most efficient - they weren't any more 'reasonable' than other humans.
Were the Greek reasonable in building the Parthenon? No it had no practical value. Were the Roman's reasonable in building their thousands of miles of roads? Yes they were of some practical use. A pyramid is NOT reasonable.