Hoyney mentioned this on SEN. They go with a different rating, when it bases the measure on the expected efficiency based on the difficulty of the kick.Can't speak for the others but Gulden is so high as he doesn't go for cheap kicks. Almost every kick Gulden does is risky and needs to be precise because he usually goes for the attacking option. Means he has a lower kicking efficiency than a player who goes for the easy sideways kicks.
A much better way to do it - at least that's one element of his algorithm that he has right.