Three points...
(1) The Bluestones are not part of the famous outer ring. They are inside the outer ring. 46 different kinds of stones and boulders are found inside the outer ring, and almost all of them have an origin that is west of Stonehenge, which is the direction the glacier came from.
(2) The theory of human transport was proposed and universally accepted in the 1920s. Incredibly, there have been only three or four published papers during the next century that support that theory. No quarry tools or transport devices have ever been discovered from the construction period.
(3) The linked paper has been reviewed and published in the open source E & G Quaternary Science Journal. The author is a retired Professor of Geography.
https://egqsj.copernicus.org/articles/73/117/2024/egqsj-73-117-2024.pdf
Thanks.
The positions of the various kinds of stone show that they were moved and set there, irrespective of where in the structure they occur. That isn’t a theory of human transport, they were clearly set up there by humans.
The site in Wales shows evidence that it was indeed a quarry, which like all quarries, relied on the presence of a useful stone.
Even if that evidence is rejected, the fact that the geology shows that all the bluestones came from one small place mitigates against random natural transport.