I get the spirit of your question but I am fine leaving it at just the players being from the country and not extending it to support staff I think that’s a better divide. The 11 on the field playing are the ones who matter most anyways.

To be a little obtuse and go a little extreme, is it just the manager that has to be from said country or position coaches too, what about trainers and other behind the scene help. Who is policing all the practices everywhere to make sure there is no outside help or do only match days count.

I think it gets a little harder to draw a cutoff line if you limit some support staff but not all because you can put a puppet manager from country in and have someone else who you would rather have as manager running everything behind the scenes. This just makes it more transparent.