"certainly goes through the barrow cemetry but is way out for the max moonrise"
Surely the barrow cemeteries are for burying the dead, and got added to over the centuries, often they are in straight lines, as if later 'chiefs/elders' are added on. For instance............ Priddy Nine barrows and Ashen Hill barrow cemeteries are both in straight lines at oblique angles to each other in the same field.... is there alignments on either of them?
Beech trees are your safest bet in wiltshire SS ;)