In real life, the Shagohod's Phase 2 as a concept would not be feasible, as firing a missile from a Shagohod-like launcher would have negligible impact on the overall velocity of the missile. The guidance of ballistic missiles is inertial, based on a known starting location, and launching it at speed and at a non-vertical angle could not be done. In addition, rockets in general are meant to be fired from a standstill, and firing them while moving makes them uncontrollable.[9] The Shagohod's use of the SS-20 "Sabre" IRBM is also anachronistic, as it was first deployed in 1976. The SS-20 appears to have been chosen by the developers because the equivalent period missiles, SS-4 Sandal and SS-5 Skean, used gantry launchers and liquid-fuel, which may have been undesirable for the Shagohod's design.
Additionally, the US and Soviet Union in real life had systems exactly like what the Shagohod is meant to represent already, respectively the Polaris and SS-N-5 SLBMs, which had been around since 1960 and 1963. Ballistic missile submarines do not need runways, can hide in about 70% of the Earth's surface and are much harder to detect. They fit into a role of nuclear deterrence called assured second strike, the principle that even if the enemy manages a first strike, they will not be able to prevent a large-scale nuclear retaliation. Shagohod would only be dangerous if nobody knew what they were looking for, and would really only be good for one launch, period, before it was relegated to the second strike role.
One point of realism, is that the Shagohod's development (as a mobile land launch system) in 1964 is in line with period Soviet missile doctrine: the R-9 missile (one of two ICBMs identified as SS-8 Sasin) was originally intended to be a mobile system to thwart a first strike against Soviet silo complexes by NATO, albeit with wheeled launcher trucks. This was later changed to a dual project developing silo-launched and mobile versions, but the mobile version never achieved the desired mobility and that part of the project was ultimately scrapped.
