Russian military has trait, they are able to disregard the number of their casualties and shrug it off just like nothing, no matter how much they are loosing. The Ukraine, if you are looking closely are somewhat also has similar trait. They are afterall has been tempered on vicious bloodbath struggle, war and revolution since long long time ago.
So there is will be no conclusion on how long the frontal war going lasted, in the end it will be entirely depend on the political will, people resolved and not only everything is about logistic and number of armament.