OK I've tried this out and in a matter of 2 weeks my scout had rated over 250 players in the Argentinian first division (where I am managing). Not sure if that is entirely realistic
But, at the start of each season you would assess each team in your division, and how good they were, so maybe this sort of scouting could be done once a season to assess the opposition and identify some targets?
It seems a bit too simple to find players this way to be honest. But you can't deny its realistic, because its not like you're travelling around the world.