I guess that aggressiveness is directly related to foul prone, however there should be some way to stop it(I do have such a foul prone player), I mean like a way that they are not telling us. For instance, It would be sad if there was a guy who is a great prospect and you virtually can't do anything with him because he is aggressive.
You can't tame Ron Artest or Denis Rodman, they are justwho they are: an earthquake waiting to happen ;-)