well, who said everybody must have different faces? some faces will be same. but if there is about 50,000 different faces - the chance you will have same face twice at your team is very very low.
few years ago i played 'HATTRICK', it was the biggest online football manager that years. there had that "cosmetic feature", every player had a face. i must say it has been much more realistic and gave lot of boost to the game.
Attachment 631
and again, the generator is very easy to make. you can make even more then 50,000 different faces!