Ling was the smartest football I have ever seen at Geelong. He was a freak occurrence. I don't think we should make a habit out of turning under performing key forwards into midfielders. There is only one Cameron Ling.
It's also pertinent to point out that Ling was a FAILED key forward as well. He had to make it as a midfielder, or else he wasn't going to have a career. Even then, it took 4-5 years before you got regular, consistent performances. Exactly what you'd expect, and exactly what we don't have the patience for now.