An interesting analysis. Ultimately, I don't see the Russian military improving. Indeed, it's reasonable to assume that they are incapable of improving. They're making the same mistakes that they've made countless times before, at least since the end of WWII. They depend overmuch on the shock of armor and the devastation of artillery without concerning themselves with joint operations, especially dismissing infantry needed to support those other branches. Witness 14-year old children destroying Soviet tanks in the streets of Prague and Budapest. The only effective bar I can see to Ukraine retaking Crimea is the US and NATO withdrawing support of such an operation for fear of Putin launching nukes.