I understand you point, it is very simple, the issue
I have with it is that it is far too simple a response to a very complex issue. I was going to request evidence from you again to prove you point, since you are going against the consensus view. But instead allow me to provide you with some reading on what the consensus view is (and to be clear, I do mean consensus, there are people with differing views on the topic and I am willing to hear them out if you want to present them, but I am not going to just take your opinion as fact. For all I know maybe you are a clinical psychologist that specializes in people transitioning cultures, but since I don't know you from Adam I will need to see research to back it up.)
The Five Stages of Culture Shock
(you'll see in this book,
which is based on a study focused on undergraduate students travelling across cultures and discusses the literature already published on the subject even mentions right of the bat some people disagree)
Back to the topic of hockey players. I think Makarov is a good example. I think Makarov was relatively unaffected by comparison to his former teammate Krutov, whose weight issues are a classic example of a reaction people having during transition shock. But that is my point, the effect is different between people, let alone between all of the categories you listed. I am not here to give any players a free pass I just don't think blanket statements on such a broad topic are in any way fair, we should approach each player individually.
I am open minded and willing to change my view if you can provide me with contrary evidence, but agreeing to disagree is fine with me as well.
EDIT - Thought you would respond to your two examples quickly as well.
First -
that two soviet migrations happened, post WWII and post Berlin Wall fall and they flourished
This is simply extremely vague, how do we know that they all did is there any economic data to back this up? And if we get any, does it mean we know that some folks didn't struggle and work thru it?
Second - Professor's transferred back and forth without trouble.
Again, do you have real evidence, even a preponderance of examples? And again, did they not take some time to fully acclimatize and produce at the highest level again? Finally, are people who are more highly educated more likely to handle change more easily? Could be, again, there are a lot of variables that go into it.