The only chance for peace maybe to divide it along those lines.
What does "lean" mean?
By any objective measure even in Donetsk-Luhansk enclave there is no "leaning" of any kind other than for unified Ukraine. The bandits want "Donetsk People's Republic", not Russian annexation. The 1991 referendum vote was overwhelmingly for independence even in these regions.
No "leaning" of any kind can be determined other than through a plebiscite free from bandits and Russian "green men". When the bandits are in jail and Crimea is returned, such plebiscite would be a good idea indeed.
Also, if you want to sound like you know something, please realize that "Western Ukraine" has a meaning in the science of geography that the maker of your map was unaware of.