Have you ever found SCOUT players on top Eleven from San Marino or Zimbabwe or East timor with a special ability or skill ?
no but you can find a Brazilian or German or Argentinian one with special skills and multiple positions...

Changing the "mother" nationality to another nationality for one token proves in a negative way that the programmers want you
to take this factor into consideration ...

The nationality has a percentage - maybe small percentage - from the overall percentage that is calculated in addition to the other factors
before the engine decides who will win the match ... :-)

To make a simple conclusion if my viewpoint , if you had to chose between two players with almost same stats, chose the one that has a
nationality better than the other according to the monthly or at least annually FIFA ranking...

I understand that it's difficult to convince everybody because to prove it requires a lot of data and a group of managers willing to study it
and share information about it.

Managers with old experience and those who are willing to spend tokens just to TRY many players with same position and stats from different
nationality will understand what I am saying...

That's my opinion and it's up to you to disregard the nationality as a factor taken by the engine when deciding the result of the matches