"but a much longer distance seems to be totally out of the question!"

That's been my theme, ad nauseam.

(Bluestone total weight) X (Bluestone Distance) = (Sarsen total weight X Sarsen distance)

ergo the two feats are similar - except, I'd rather maul a bluestone around than a sarsen, so actually the sarsen feat ought to be far more celebrated.

Imagine finishing the sarsen job and finding out that people in future from China to Alabama would only be singing the praises of the Welsh project.