All one has to do to appreciate the amount of rocks that can and will be deposited by glaciers is drive the back roads of Southern New England during Winter and observe the stone walls built by farmers who had removed them from their fields.
And thats in an area that was agrarian for maybe 250-300 years, not thousands.
Glacial movement may or may not be what happened to bring the boulders to Stonehenge, but it can’t be ruled out as a reasonable possibility.
Indeed and it makes for a beautiful part of the world, New England.