Years ago I read a superb book about the 1945 fall of Berlin, ‘The Last Battle’ by Cornelius Ryan. The front-line Soviet assault troops were disciplined and professional.
But after them came all sorts of rabble. Many were conscripts drawn from Soviet minorities. It was those latter troops who did most of the murdering, raping, and looting. I suppose the Chechens would play that role in Ukraine today.
If Putin is aware of this, I wonder if he would care.
The Russians in 1945 had tens of thousands of trucks that the Western allies had given to them, allow them to transport millions of second-tier troops. Putin is very limited in what he can do - it took all his resources to get 180,000 front-line troops onto the battle line.
Transporting 70,000 troops 500 miles, and feeding them and supplying them with clothing and ammunition might be a tall order nowadays.