Wait, wait, wait!
The article is totally erroneous. These modern Druids are a rather recent invention, and they are not descendants of the original Druids. The historical Druids themselves have nothing to do with Stonehenge, which is thousands of years older still.
Modern Druidism is a synthetic religion having nothing by name and a few superficial similarities with the original Druids.
You answered the question that immediately popped into my mind - i.e. how much (if anything) do these guys have to do with the original Druids?
Thanks!