I have had orthotics made for the problem. I am running now at about 175 pounds. I claim no expertise in the matter, I'll just relate my understanding.
Motion control comes from the ability of the shoe to guide the foot as it falls.
Since cushioning isolates the foot from forces in the shoe, forces designed to guide the foot may also be isolated. The insoles add very little. Take an insole, put it on a sidewalk, and hit it with a hammer. You will feel quite a bit of shock from the blow. If you hit the rest of the shoe at the inner heel on the same surface with the same force, you will see where most of the cushioning is coming from.