I asked not about countries but about ethicities.
In many countries outside of the West ethnicities have a symbiotic relationship with the countries they are citizens of.
You even acknowledged this when phrasing your enquiry and these particular groups having a "national character."
On their own there are a lot of positive qualities found with Russians, Ukrainians and Belorussians in terms of culture, cuisine, etc.
Things turn negative though (and all three are guilty of it) when one group seeks to dominate another. This is often done through demonizing and even denying the other's very existence; preventing the learning and use of the other's own language; or denying fair public representation in places like government, the courts, the education system, etc.
Whether it is genuine or rigged, there is no denying that ethnic Russians in Ukraine have been involved in appeals to Russia rather than Ukraine to address their problems.
Over many years now Poland too has prioritized raising concerns and mistreatment of Polonia with the governments of the countries where they live (such as Ukraine and even Lithuania). Poland has programs to repatriate and reassimilate these Poles back to Poland. Unlike Russia though, Poland has never even sought to retake lost land where Poles still live.
