And they aren't. Of course I think you're sane, but your analysis is limited to the Russian Army against the Ukrainian Army. Let's follow your reasoning. Russia's military will never get it together. When Ukraine gets all the weapons promised, the summer comes, it will go through Zaporishzhia like a hot knife through butter. I wouldn't be at all surprised. Ukraine will make Western Crimea untenable. Russia will retreat easterly. All good so far.
But then what? Even if Putin leaves the scene. What about Girkin, Prigozhin, or whatever other operator rises from the ashes? What does the Russian military really have to do with the Russian mafias? If the U.S./EU won't enter Ukraine because of nukes (as you've said elsewhere) who would enter Russia to enforce anything?
No one.
If Putin ordered all the troops home tomorrow who would have won? Russia. Ukraine has been critically wounded. Who's going to pay to rebuild, especially during a global recession? Will Ukrainians own what's rebuilt, or Europeans, Chinese and Americans?
Once Russia left, sure, the U.S. would help keep Ukraine armed. But with F16s? We won't even give those to Europeans. Where would Ukraine get the money to buy them? Ukraine will become a beggar nation. (I feel the same way you do I believe so it doesn't make me happy to say that. But as you say, follow the chain).
Then shadow militaries and mafias will prey on Ukrainians. Fine for all the politicians to talk democracy in Kyiv, but the rest of the country? Most of the country could make previous corruption look like child's play.
Again, hope things work out just as you say.