I agree with Russia. Till now they don´t have problems with this team. Russia has a great history with many nations and till now nobody had problems with them, only Paraguay. Russia is nearly the same as Soviet Union only smaller countries became independent.
The flags are only flags, and not it is not the same like Argentina can for example represent Paraguay. Paraguay wasn´t part of Argentina(in the last decades) and you aren´t related to Paraguay. And it is good that till now nobody had problem with Russia´s nationalities, only you...
The today´s football: there are black people playing for example in France or England-they say they are French and English. Most of them haven´t even born in France and England. So I don´t know why is it problem for you. Ukraine and Uzbekhistan were the part of Soviet Union which was one country, so they were born in the same country.
What if they have two nationalities, Ukranian and Russian as well? For example I live in Slovakia, I am Slovak citizen, but I have Czech and Hungarian nationality.
Now if Catalonia will be independent country, they won´t have OSM team, people from Barcelona for example will play in the Spanish team as well.
First think about what position are they in. You can´t 100% understand them.