Well, that might solve the question of how you polish small stone surfaces flat, but some of those blocks are as big as a school bus.
How do you maintain precise flatness, squareness, and dimensions over the entire exterior of an object that size, unless you have the equivalent of modern cutting and measuring tools? Its just not possible to do by hand.
Even if it were, we're talking 2.3 million multi-ton blocks you'd have to quarry, cut, dress, transport, and set in place. We wouldn't attempt such a daunting project in our time, with advanced technology, but egyptologists insist that the ancients built the whole thing within twenty years, using nothing more than copper chisels, stone pounding balls, ropes, and brute force.
Not only that, it was so easy for them, they built two more giant pyramids on the same site. And just for good measure, they carved a massive labyrinth of tunnels into the solid rock under the whole complex.
To top it all off, they didn't leave a single inscription or hieroglyph upon any of these monumental structures throughout the country, nor did they record the magnificent accomplishment of these massive constructions on any papyrus, stele, or temple wall.
Who knew the pharoahs were so modest?
Taking a mere 20 years would be quite a challenge.
I wouldn’t necessarily expect that the smoothing apparatus was taken to the stone — perhaps the stone was taken to the smoothing apparatus. It would imply measuring tools of near modern quality, but not necessarily an engine as we know it.
At any rate it is a yet unsolved puzzle. If I wanted to do something like today, I’d cast the blocks, maybe even in place. But these blocks were not cast; they were cut and finished.
But if the craftsmen were told that they MUST built a pyramid out of cut stone like this, or off with their heads, I think they’d start getting VERY ingenious, if they were otherwise granted all the labor resources that the ruling pharoah could command.
If it has to be as big as a school bus, it does. But a single grinder run by means of horse or camel power might be constructed to scour one of those surfaces as a whole. Sliding the face of one such block back and forth against the face of another such block with a crude grinding compound or mud in between? What we see today has been weathered by millennia of wind-driven sand and might hide the finishing marks.