It would never be possible to hit 100%. Nothing is perfect. But it would be able to change from 'Widespread' to 'Thorough' status with these steps i think:
1. Recruit scouts from their native region. They learnt specific countries knowledge faster. For example: A South American scout to scout South American Region or a Eastern European to Scout Eastern European Region.
2. Recruit scouts that have vast existing knowledge. Such as ex-Man Utd scout Tom Vernon (Western African knowledge) or Macsin Fastyn (Eastern European knowledge). They already have a number of countries covered.
3. Keep bothering your board to find feeder clubs for either 'financial benefits' or 'extend scouting knowledge'. For example, if you have limited scouting range, get your board to feed off other lesser continental reputed clubs like LA Galaxy where they themselves had feeder clubs on their own and they may be from another continent. That way you not only will have North American knowledge but you also siphon knowledge gained from Galaxy's feeders.