Claudius have you ever hired anyone at your university? Think about how tedious it is to find the right person. Why should hiring people who make £10m a year be easier?
1) Sports are extremely quantifiable in a way that is extraordinarily unusual in most jobs.
2) The higher the level of the position, the fewer potentially qualified candidates there are. It is higher leverage, but it should certainly be "easier".
Overall, talent is going to be power-law distributed so scouting for Celtic is going to be more difficult than scouting for Arsenal since the people you're sorting through are going to be more difficult to distinguish between. However, at the level of Arsenal, I really think just sorting by Fotmob rating and applying an age filter will get you pretty much everything you would want.