Hi Jon,
The Orion correlation is usually calculated assuming a perfect fit between the first two stars of Orion's belt and the apexes of the first two pyramids. The result is the third star misses the apex of the third pyramid by about 49m west and about 20m south. Moving the originally intended apex of G2 to the north and the east would make the Orion correlation dramatically better, because the shorter distance from apex G1 to apex G2 would mean the relative distance to point where the third star should be on the ground will be shorter (less to the south and west) and the point would be even less to the south and west because the starting point of the line from G2 to G3, at the apex of G2, would be less to the south and west, assuming that the originally intended position of the apex of G2 was supposed to be north-east of it's existing location.