“The Ukes are down about 75% of the army they started with. They’re in no position to stop anyone.”
Then again, why hasnt Russia finished the job? They have little opposition.
Are the only choices that they must either have won completely already or they are losing? That seems to be what you're trying to argue. The Russian tactics have been to just pulverize everything with their arty and then mop up once everything's been shot to pieces. Why take losses if you don't have to?