The idea is, you do a friendly to test these players, so thats one work. Then, you can prove these players in freekicks and corners, ofc. but, if, theres one or 2 corners and they fail, prove another player in this work, you don't need to test all fouls during 90', just 1-2 freekicks/corners, because usually, there's a player in the team, that take freekicks better, and another that takes corners better too, so, if you can find this man, thats a +1 and thats another work interesting to do, apart from test the players during the match and see how they work, how they contribute.
Thats a 2nd work, because you can have a key player, ST for example scoring 1 goal per match, but bad in fouls/corner kicks. And probably inside your team will be 1 player that will convert in goal, the 70% of the fouls that pick, or the 70% corners despite that maybe will participe less. Like my David Beckham now.
I did now a friendly, for example, and the only corner finished in goal, and the 2 fould the same.