You do not need 100% scouting everywhere to have 100%wherever you want it. Some scouts have alot of spare knowledge. Furthermore a scout with NO knowledge of say South America can scout the whole continent. You just need a coach or physio that knows that the country exists.
If you treat scouting as a dynamic activity then you don't need 100% anywhere, you just scout the region with one or more scouts, you have 100% for a short while, in that time you can try to identify the best prospects for your team.
A little secret which you can use if you have more patience that I do....
You can scout players manually that you do not know exist and cannot find in the player search function. If you go manually through all the clubs and manually scout all their players then you can operate with 0% knowledge of an area and still get perfect scouting results. Very tedious, but possible.
I typically send a scout on a scouting mission to a country or an area and once that scouting mission is finished I have him manually scout all the players in that region, typically at a rate of 4 per day (120 per month, 1440 per year). If you organize your effort and have as many scouts as possible (board limit +1) even clubs in the lower half of their top leagues, upper half of second leage or top in small countries can scout the entire world. Very tedious as well to click through 40-70 scout reports you get per day, but if you hold in the space bar the computer flies through them... | 
