A lot of those "radar-guided" missiles that the USSR had were, in fact, command guidance.
This goes for the 2K22's missile as well.
IMO, it's a shame the 9K330 Tor/SA-15 isn't in the game.
You are saying the truth, the OSA use command guidance. The first soviet missiles used pure command guidance, but latter missiles switched to another more accurate terminal phase guidance. The only pure soviet infrared missiles present in the game are the Strelas, Igla and Strela-10. I actually think that the OSA is probably too inaccurate on a realistic side, but I think it's a balance choice. About the Tor missile, the reason that it isn't in the game is probably because it entered in service in 1986, one year after the end date of the game
and probably because it would be too powerful