Excellent article on Afghanistan

[Marcello]

Russian commanders just did not have the training or resources to nation-build.

The Najibullah regime outlasted (if briefly) the USSR itself while the US & Co were pumping aid to the Mujahedin even after the soviet withdrawal years earlier. Which means that at a minimum that the Army that the soviets had trained was at least somewhat effective. I would not bet much on the current crop in Kabul faring better.

The extreme major of Red Army soldiers serving in Afghanistan volunteered.

I doubt it. Any source for that?

What about counter-revolution? What about Hungary in 1956? What about Nazi insurgency in 1944?

It should be note that Hungary did not put up an organized resistance and the local conditions were not favorable to an eventual insurgency.
Whatever "Nazi insurgency" may have been around in 1944 was a small scale thing, just like anti soviet leftovers in the Baltics and such which were not eliminated until years later. Such things barely registered on the radar, if they did register at all. Large scale COIN abroad was something new indeed.

In addition, the Soviet divisions did fight in Hungary, Vietnam, parts of Africa, etc.

Soviets did fight in Vietnam, Korea and others places, but not as divisions or in major force generally.