I see no evidence of war crimes, in fact the entire point of mechanized armored maneuver is to enclose large swaths of enemy fighters who refuse to stop trying to kill you and invade your country in order to force their surrender with minimal fighting. Yes you can use it to conquer territory filled with people who don't want you there but it is an illusion since you will be simply resisted by guerilla forces rather than an organized military and you will lose all the same.
There is no other reason to be proficient at it, which is why russia isn't, they already treat their own soldiers like worthless prisoners, at an institutional level the russian military is incapable of understanding the value of alive human beings and it is why they have lost this war.
If you want some war crimes how about how poorly russia treats its frontline troops in the Pokrovsk area? All Ukrainian forces really had to do after all the operational planning was ernestly offer food and shelter to get the russian fighters to surrender, which reveals how pathetic and murderous the russian military is towards its own people.