I don't believe that. Without professional fighting, he'd already be dead or doing a life sentence. If our society can advance far enough to get him that far, we can get him further.
War is one of those people that they don't want in the world, but need. He's a warrior. If there was a legit war going on, you'd want people like him defending you. They have a hard time functioning in regular society, but as evidenced above, we can fix that and help those people function in peace time.
I wouldn't want a mentally disturbed man defending me sorry.
If he can't act in a calm manner towards people on a normal day to day basis and routinely beats the shit out a loved one on a day to day basis culminating in attempted rape and murder putting him in one of the highest stress environments known to man is just fucking ludicrous.