> If Russia can provoke any NATO countries to attack first by, say, downing some airplane of theirs (fighter jets, recon, strategic bombers, etc.), they can use this as casus belli, and use it as propaganda.

This has already happened, Turkey shot down a Russian jet in 2015, the Russian state very quickly tucked its tail in after that. The VKS can't afford to lose these planes willy-nilly.