In authoritarian environments, any compassion you show the declared enemy is a grave offense and needs to be punished severely.

The russian soldiers are in an awful predicament in this war. But they are still the aggressors and Ukraine has the right (obligation even, seeing what Russia tends to do to civilian population it conquers) to defend itself against them…and as awful as these weapons are, they have not been used in an illegal way here according to international law (something that Russia doesn’t give a flying fuck about, btw.).
Personally, I don’t see a moral issue here though I of course would prefer if noone had to die of which only happens in the case of Putin withdrawing his troops right now.