Glad I found you. Excellent analysis. I love hard analysis mixed in with some humor. I'll just point out that it's easy to forget what we're known from day #1, no one wants to fight for money if the odds are high they'll die doing it. Everyone is an opportunist. Even someone in the Wagner group is not going to want to come in contact with a battle-hardened and experienced group of Ukrainians and foreign fighters.
That begs the question, what percentage of men in the Donbas will fight for Russia. I have no idea, do you? My guess is most will find a way to go hide, just like their poorly equipped Ukrainian counterparts on the other side. In the end, you'll have Russian die-hard fighters against Ukrainian die-hards (if we're not there already). But again, if you're on the Russian side it's easier to avoid getting killed (which means Ukraine will continue to shrink Russian forces, the weak, etc).
The next thing that I wonder about and don't understand why more isn't written about it. To me the Donbas is political. The South is an existential threat to Ukraine. Ukraine must break Russian supply lines and support between Kherson and the East. It MUST drive down to the Black or Azov Sea. When will Ukraine try this?