Haven't read the link in detail, Nigel, but will later.
I think that, for what you are suggesting to work, the setting positions of the moon as seen by the observer would have to move from day to day in a way which corresponds with what the moon is actually doing. But the observer doesn't necessarily see what the moon is really doing because of the effect of refraction.
Here are some quotes from Douglas Heggie's "Megalithic Science".
"[Refraction] makes the apparent altitude of a rising or setting body higher than it would be in the absence of the atmosphere by an amount which can exceed the apparent diameter of the full moon. ....
Atmospheric variations vary from night to night, and the resulting variations in refraction would have limited the usefulness of very accurate orientations even in megalithic times. In other words, unless conditions then were much more stable than they are now, these variations impose a limitation on the accuracy with which a fixed megalithic orientation could have been used to record a fixed astronomical position. ...
Refraction is particularly subject to variation just above the level of the ground ... [distant foresights] tends to make refraction stronger than it would be otherwise. Perhaps it also implies that the declinations defined by these lines can now be determined only with added uncertainty, and that their possible use in megalithic times was rendered particularly troublesome."
As an example, he adds
"... refraction changes would have prevented the use of the accurate natural foresight at Ballochroy, Argyll from determining the day of the solstice since they much exceed the daily variation of the declination of the sun at the solstice."
In other words, what I'm saying is that refraction is not simply a problem to modern day surveyors trying to measure and replicate what was seen in the past. It was also a problem to those trying to observe and record movements in the past if they were trying to achieve highly accurate recorded positions which they could return to a year later or whenever and expect to see the moon or sun in exactly the same place as it was when the recorded position was set up.
I'm not anti-alignment; just unconvinced by many of the claims for very high accuracy.
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