I'm not saying they don't, but any set of three equally-spaced, but slighlty mis-aligned objects could match Orion. To me they look as though they are part of an arc. The car park holes were only found because they built the car park Has any investigation been done beyone that to see if there are any more?

By joining adjacent pairs and then projecting a right angle from the middle of each line, the centre of the circle (if they are on a circle) would be where the lines cross. Does such a centre make any sense in the context of any other nearby archaeological features?