Hi EugeneF!
Well, it might be that in Soviet times a little confusion was indeed intended to mislead the west and to achieve a favorable situation in which, lets say, not 64msl but 128msl would be available in fact and so to exceed the agreed limit of 100 interceptors a little bit.
One the other hand such kind of tricks would be probably noticed by the US and they would have complained about it, like they did with that other little trick - I mean the Krasnojarsk ABM Radar.
But sometimes it is worthwhile (but costly) to try those little tricks. And if you look to the (published) Data Situation in that Soviet Military Power effort of the 80ties you can see that they assumed four Long Range Sites with 16msl each, or maybe four Double Sites with 8msl in each single node but not to exceed 64msl as a grand total.
Regarding the true purpose of that Documentation, namely to serve as Propaganda (they never provided such information e.g. for China or Iraq) and to heat up the population in Europe to get willingly prepared for that Re-Arming effort with Pershing II and Cruise Missiles, we can assume a tendency of overestimating things. Although in a much more primitive way, such effort was repeated in 2003 when Collin Powell obviously was forced to tell fairy-tales about Iraqi WMD.
The fact that they didnt overestimate those numbers could mean that maybe they had no better intelligence data at that time and the little trick worked, or there never were actually more than 64msl in the basket.
Whatsoever, the past is past the reality today is that there are obviously two reliable Long Range Sites with 16 silo launched SH-11 Gorgons at each site (Sergiyev Posad-15 and Naro-Fominsk-10) and five Short Range Sites with a total of 68 SH-8 Gazelle.
So the A-135 System of the 90ties has much the same pattern than that of the former US Safeguard System.
I think those systems are of no sense in respect of the classic scenario in which hundreds of MIRVed ICBMs easily would saturate such a defense. Maybe this is the reason why the US retreated it very early. But nowadays, in a scenario which sees to have Iran, Pakistan (and Israel) within a 5 years period armed with just a few dozens of single warhead IRBMs with a Range of about 3000km, such a System indeed do make sense to protect vital cities and installations. So at least Moscow seems to be well prepared to withstand any such blackmail with its umbrella of A-135 and S-300/400 and the rest of Europe either hopes such things will never happened or is waiting for new and costly toys made in US.
Best Regards