"Only some of them are convinced murderers and rapists, so they're really very nice people."

There doesn't exist enough napalm to give each and every invader exactly what they deserve.

Wagner is literally recruiting violent criminals. These aren't tax cheats. The system most highly incentivizes those serving the longest sentences, so it's the murders and rapists that are first to volunteer. So I am indeed short on empathy, but I think it's you who is short on critical thinking.

Given that Russia (through its predecessor, the USSR) still holds the world championship for civilian rapes (Berlin, 1945), then maybe you think that the Wagner guys are indeed just regular Russian soldiers...

He must have noticed how they moved his desk next to the window, and keep offering him tea.

There must have been a children's hospital of strategic importance that needed bombing, or perhaps a tactically critical old folks home.