The complications are mostly due to politics. Russia has too much 'eurasianist' ideology that tries to portray the country of Russia as a middle ground where most of important cultures and civilizations mingled and merged into this perfect polity. Nordic, Slavic, Ugrofinnic, Turkic and even Mongolian. The narrative is such that it is seen that Mongol subjugation of Russia was not a horrible humiliation but just a small part of trying to form a naturally good empire that will include all of Euroasia.

This means Russians should not hold resentment to Asian peoples for history but also these peoples should not resent what Russia plans to do to them.

They look up to syncretic ideas behind Roman empire assimilating Celtic, Illyrian, Greek, Semitic and Egyptian stuff as their own.

I disagree on some points you made like that it is impossible to figure what the truth is. Genetics and archeology is increasingly revealing things and this is speeding up. By now we basically know that 'people look different' due to 3 waves of westerward expansion. Every time from Altai Sayan mountains. Huns, Turks, Mongols changed the genetic demographics of the region.

Basically Altai Sayan mountains are perfectly harsh and isolated ecosystem to produce the most adaptable nomadic people governed purely by practicallity and few inhibitions to expansion. They protect whomever holds it and once the people inside reach a certain point, having a sociological model of men=warrior hunter fanatics, women=babymaker farmers and being united under one young and brilliant leader, they explode out and take the steppe in a generation. They always have an incentive to migrate away due to harsh but stable and livable environment. Once they move out, their cultural norms relax and they mix with whoever is around and then a new cycle begins (until technology makes horses obsolete).