Most of them are useless, even the aerial defenders. However the vast majority of the goals in the game are scored form set pieces, one-on-one situation and long shots. Too bad we have playmakers and dribblers and not a long shot specialist. If you really want a 0 to 3 assists per season player make him a playmakerDribblers never dribble anyone and penalty kick takers usually miss more penalties than the non specialists.
P.S. And yes, the only useful ones are the free kick and corner specialists, they have more assists than average.