Lee doesn't have the build or footwork to play with his back to the basket at this point. He would be excellent at high post screens and roll to the basket for lobs.
It's happened a handful of times, and he just isn't that good at it. He's going to excel as an energy guy that finishes off of dishes and lobs as well as cleaning up the glass
When these teams are packing the paint somebody has to shoot the ball. Too many turn-overs on the interior trying to dribble drive. You can't expect much from Lee if there is no room.