You're right, Putin's reasoning could be completely wrong, but he may be able to continue pounding the Ukraine for some time, as there appears no immediate threat to his rule nor enough Ukrainian opposition to stop him in his tracks.

I'm thinking that in a 5-year window however, Russia/China perhaps Iran may be in trouble. Their repressive Nationalism creates a "brain drain" to more Liberal Democracies, while conflicts will take their toll on their morale and economy. Militarily, we are learning that Ukraine (and probably Taiwan) are difficult conquests that tend to strengthen/unite the NATOs, ASEANs, and SEATOs. It would appear that as in WW II, freedom begets better minds and more productive workers...later better weaponry and tactics.

Look for Russia and China in 5-10 years to "relax" their policies (if not experience major regime change) as they did in the 80s-90s, to allow their economies to recover and save face. Meanwhile, look for many more nations to join these treaty alliances to offset Russia/China's hegemonistic aspirations. Hopefully Western democracies will also regroup along sensible lines.