There is one other connecting "link". Close to Carn Meni is Bedd Arthur, which is described as a rectangular hengiform, which is similar to Stonehenge horseshoe shape;

http://www.themodernantiquarian.com/post/45,

the above photo shows its shape and its nearness to Carn Meini - I'm on the transportation side of the stones, don't believe it was glaciation ;)