just no. there are not 10s of thousands of precision artists working on this or at any time ever. the best you can hope for are tens of thousands of UNSKILLED day laborers or slaves working a piece with crude stones and maybe one artisan per project to get the measurements just right. these things are gargantuan in size and just one piece would take one artist many years or even decades. the precision and smoothness are whats important. you can hack away stones with many people but it would take a MASTER to shape something like those carving and there were many many of them.
Undine Rising Frome The Water by Chauncey Ives 1859. made of marble
Dimensions. 60 1/2 × 19 × 15 1/2 in. (153.7 × 48.3 × 39.4 cm)
one Master and it took him countless hours to carve this 5 foot tall sculpture out of marble which is softer than granite. with modern steel tools. each of those many many ancient egyptian masterpieces, some of them massive would have taken many lifetimes to accomplish. so i repeat, no. those carvings had to have been created in a more modern fashion. with tools egyptologists say they never had.