You should study history deeper than what you've been spoonfed. Your two peoples have NOT always been the same. Indeed, more of what is now Ukraine was Scythian Iranian than was ever "Rus." Celtic tribes left material culture there. Slavic tribes with more in common with Poland and Moldova than the Kievan Rus developed material culture across more of the region than left by the Kievan Rus. Ukraine's material culture dates back as much as 5,000 years – eons before there was a Rus state or even a dream of a Moscow.