in my eyes help defence is represented in the actual game engine through the ratings, good offensives player helps to get easier shot for teammates in increasing the offense rating(or if you see it more real, in getting more attetion from the other defense).
Good defense helps to defend.
For example oi got too guards with inside shot 1,but the made also a lot succesfull layups when i am plaiyng LI. If i compare that with free throws a player with FT 1 miss the basket nearly everytime, cause he got no help.