I don't get the Russian strategy (or lack thereof).

[EX500rider]

66. Unfortunately they have a large stockpile of S300 SAM missile, like 7,000

October 2, 2022: A survey of Russian anti-aircraft batteries, using commercial satellite photos, has shown that Russia has been shutting down S300 (surface to air missiles) batteries around Russian cities and moving the missiles and launchers to the Ukrainian border, where the missiles are used to attack surface targets. The new S400 SAM began replacing S300s about fifteen years ago, but progress has been slow because of economic sanctions imposed in 2014 and 2022, The military budget has declined and the S300 missiles, radars and launchers are not getting any upgrades because the S400 is much more effective (with twice the range of the S300) and one S400 battery can do the work of two or more S300 batteries. Mainly this is about the sanctions making it impossible for Russia to manufacture new guided missiles to use against Ukraine. This is why there have been fewer guided missiles used against Ukrainian targets in the last month but a lot more less accurate unguided missiles and S300 SAMs. At least 500 S300 missiles have been used so far against surface targets in Ukraine and there are still 7,000 S300 missiles available for hitting surface targets. Some S300 batteries are still used in Ukraine or from Russia. Not a lot of these are needed because the Ukrainians have developed systems and tactics that minimize the effectiveness of the S300 as a SAM.

Back in July Ukraine warned that Russia was beginning to use its 1.8-ton S300 (SA-10) SAMs as SSMs (surface to surface missiles). The allegation was based on Belarus revealing that they had recently tested S300s used as SSMs. The S300 was known to have been designed with SSM capability. That means one of launch options includes SSM mode. There are two major limitations to using a SAM as an SSM. One is accuracy at longer ranges. Russian SAMs are guided to the target using a ground-based targeting radar that guides the S300 to aerial targets up to 150 kilometers away. SAMs are programmed to self-destruct if they miss their target so that the missile and its small (100-200 kg) warhead does not land on friendly territory. Used as an SSM the self-destruct is disabled and the guidance system aims the missile at a ground location, but with less accuracy than against aerial targets. Russia has apparently modified the SSM option to include a GPS option that directs the SAM to a specific ground location. The GPS option works, but not as accurately as expected. Ukraine believes that the Russians are running out of SSM missiles and using S300s as SSMs because there is not much need for their SAM capabilities, especially with the more recent and capable S400 now available. The Ukrainian prediction was apparently correct.

https://strategypage.com/htmw/htada/articles/20221002.aspx