There's no ethnic cleansing in Ukraine - Stalin (a Russophile) already did 99.9% of it back in the late 1940s and 1950s.
Stalin relocated the Tatars to Central Asia - only a small number returned
Stalin relocated all the Poles (200,000+) in Ukraine to Poland, in Operation Vistula.
Stalin rounded up any Germans on Ukrainian soil and sent them to Central Asia
Stalin scared the Jews so bad that most fled for America and Israel.
It was ironically Stalin, despite Ukrainians who hate him, who otherwise made Ukraine a relatively homogenous nation (with Ukrainian and Russian language) from an ethnic point of view.
Russia itself isn't homogenous either - it's technically less homogenous than Ukraine. If Slavic is the race then Russia is very heterogeneous from all the Finnic people, the Asians / Tatars in Siberia and then the Caucasians in Caucasia.
It was Khrushchev who had to complicate things by transferring Crimea over to Ukrainian SSR, as Crimea was populated by Russians who descended from Russian Russians who didn't have anything to do with Ukrainian people or culture.
Khruschev could had avoided a lot of problems had he transferred Kuban (instead of Crimea) to Ukraine. Kuban was already full of Ukrainians (Kuban Cossacks who descend from Zaporozhe Cossacks from the Polish-Lithuanian Commonwealth, although they are Russophile and speak Russian).
At least that way, Russia could have had help in the 1990s against the Chechens and all the Georgian crap would be Ukraine's problem.