Glad you got a kick out of the S-25 sites. I found some old CIA diagrams of the Moscow air defence network after I'd finished and I was pleased to find that I had basically a perfect match.

As for the locations of the GORGON sites, your explanation seems perfectly plausible to me. Given the fact that one of the facilities matches up with FAS imagery and the fact that they do seem to match known locations, I'd guess that these are the GORGON sites. Makes sense to co-locate them with existing SAM sites for added defense, security, and logistical support.

As for the fifth location (which is at what I have labeled as either SA-1 Site #25 or #27 for anyone else interested), it may be either a test site (probably not, that stuff is done at test ranges), an incomplete site, some sort of command facility, or something else entirely. Or it could be another GORGON launch site.

My theory? They simply placed two sites to the northwest, two to the northeast, and one to the southwest. If you look at the locations of the two northeast sites, they are on either side of the given location on the overlay. Probably they were close enough that people got confused (like if they were both called "Aleksandrov Launch Facility", for example) and eventually it was assumed that there was one site when in fact there were two.

Also, these sites could be matched pairs for Moscow defense, with the extra fifth site down in the southwest being positioned to defend the DOG HOUSE and CAT HOUSE radars which are nearby.