Did they have graph paper in the Neolithic?
It seems logical (possibly) to line up things that are intervisible.. but things that are over hills? well I suppose you might want to.
Also a stone circle would be more Bronze Age, wouldn't it? Whereas Silbury and the Sanctuary are they not older? Not that you can't line things up that aren't contemporary of course.
Don't know what I'm getting at really, just I would feel cautious I suppose. And I'm waiting for the L word to come up probably.