Such mode of thinking is potentially dangerous as it emulates a mode of thinking back during the days and era of the Russian empire
Back during the Russian Empire days, the imperial ethnographers did not recognize Ukrainians and to another extent Belarusians as distinct from Russians but rather variants of one people denoted "Russians" where todays to then, Russians were Velikorussians(Great Russians), Ukrainians where Malorussians(Small Russians), Belarusians where Bielorussians(White Russians)
Ukrainian thinkers at the time had a problem with this classification, seeing it as pejorative as being seen as a small version of a group of people is generally bad
Lenin did combat Russian Chauvinism in this regard by recognizing Ukrainians as themselves
Is this because Russians and Ukrainians are Ethnolinguistically Eastern Slavs. If so, I find this mode of reasoning to be rather shallow, because it assume people groups are the same based on grouping and this cannot working by looking at other ethnolinguistic groups, for examples semitic people who encompass, Jews, Arabs, Amhara, Assyrians, however saying these are all essentially the same, because they have already diverged, over millenia, and even within their own groups, there is already a great deal of divergence by regionalism, religious differences, traits such as those
Unless there is an exception, I cannot see how this take is rational and intellectually sorted
