Regarding the orientation, I suppose there's the possibility that they might want to replicate the shape and also point it at Orion, so they could process towards it/ and symbolically "along it"???
About the other monuments and if they fit into a star pattern - I'm not going to look, as I know that way lies Obsession!
Haven't checked out the M6 yet for Orion alignments (!!) but if you say that's how it was built then who am I to argue?!
Actually, I'm normally the biggest fan of saying these things are probably coincidence, especially where there's only 3 elements - the first 2 come "for free" and it's only the positioning of the third that matters. But, given the other possible connections here, the level of accuracy DOES make me wonder. Looking at the accuracy another way, the proportionate distances are exactly right, and if only the centres of the top and bottom henges had been perhaps 1 ft 6" to the right and the left respectively there would be no discernable error at all compared to Orion. For such a big monument, that's thought provoking at least. If it's deliberate it really is amazing, and the question would be - if they did do it, how on earth did they do it? I couldn't, just by looking at the thing in the sky, and I'm a surveyor.
So I think we're into the annoying situation of saying it's a big coincidence simply because it's TOO accurate to have been fashioned that way. OR, they fashioned it that way, and got it very accurate by coincidence....
Enter Steve Gray, who will explain all....