There is one problem I notice which is only tangentially related to ratings and more related to the engine itself.
Getting the ball to an inside player is not ONLY about the passing skill of guards. Better inside players are better at getting the ball. They gt better seals, they provide better targets, they have better hands, there are a huge number of factors.
The guards ability is relevant, but I believe that a teams ability to get the ball inside is more dependent on the ability of post players to create the proper lane than the guards ability to put the ball in his hands.
Imagine trying to get the ball to Shaq or Duncan in the post, then imagine trying to get the ball to Kwame Brown in the post. The first 2 are much easier to feed than the last one because they are better at getting in the right position.
Passing the ball inside is actually ridiculously simple when you have bigs who know what they are doing.
The game engine seems to put way to much emphasis on the guards in terms of getting the ball inside.