I agree Mr. Z. I've seen people who have trained for years who weren't that accomplished as martial artists. That being said I've also people who with no training just seem to have an intensity about them that says, "you want some of This?"
This goes back to the A + B = C of TMA. The untrained guy just might plow you through the wall. With what technique one might ask? The freight train through the chest amd watch them get slammed to the pavement technique.The untrained aren't burdened by the "you punched ..now I counter of TMA. My two cents worth. All that said I still like TMA alot. That's just me.

keep training, Mark