@TonEdi - I've got a bit of experience, firstly being a migrant myself here in Australia and secondly being from a country (Austria) which has had migrants from its own close 'territories', territories acquired mostly by marriage or default, not conquest, over centuries and people do take on the new 'nationality' very quickly.
I have done genealogy research on my own family and was astonished about things I hadn't noticed as a child - like that my aunts all spoke in a strange language when their gossip turned - shall we say - salacious . They spoke the language their mother had spoken, Czech. I never learnt it, but it helped my mother after WWII to deal with Russian soldiers who came with evil intent in the middle of the night, but left having been sat down, given a cup of coffee and them showing photos of their families. Speakers of Slav languages can communicate fairly easily between themselves.
On just scratching the surface of any of my friends from the 'old country' it is common to find that they have an ancestor from a different country, Italian, Hungarian (my husband) Yugoslav (many now living in Austria), Czech, Polish, Roumanian etc. etc. are common - the best Comedian in Vienna at the moment has an Iranian father - one of the most popular singers has a French father - and now there is a large Turkish population in Vienna too and in the rest of Europe, too, along with all the displaced people losing their homes due to unsuccessful NATO interventions in their countries of birth.
Experiences in Australia:
I have experience with displaced people at a local club here in W.A. all German-speaking people, who were driven from their homes in Eastern Europe, some of which their families had occupied for over 200 years, but they had not adapted, because they felt superior to the locals. So, after the Hitler horror at end of WWII, they were driven from 'their lands' - which their ancestors had purchased and worked, and which was swamp land mostly, but had been turned into productive land by these new and hard-working immigrants - similar to what happened around the world with many other ethnic groups.
One reason for the migration East of many poor Europeans, not just Germans, was the devastation the 100-year long Turkish wars had caused in Eastern Europe - which went as far west as the Coast of Croatia - by the way - and one of the Habsburg emperors gave away land and start-up money to migrants who could make the devastated country-side fruitful again. And they did.
I don't know enough about the Eastern Ukraine, but know that the Western Ukraine is very pro-West, it too had German speaking migrants over the centuries, so there is a natural leaning towards Western and more progressive ways.
Ethnicity will always be a bone of contention when people are poor and times are tough or dangerous, then its 'out with the newcomers' 'intern them' and 'lets grab their possessions' etc.
I am not a specialist on the Ukraine, but do know about shifting the border stone stuff, the land grab etc. which is so easy to do in land-locked countries.
Lucky Australia, we are one wonderful country on an island continent
Go well
Taurisk
