To whom are you directing your remarks? Did I miss someone's post who said that aikido makes one "invincible"? All I've seen are posts from, for the most part, many people who have experience in other martial arts...
One of the greatest teachings of D. Hooker Sensei at one of his seminars in Tallahassee was a reminder that we must beware the "superiority attitude" of "I know AIKIDO!!!" lest our egos start writing checks our bodies can't cash....
Dennis, as usual, is pretty much on the ball, but you do know that he also studied other martial arts outside of aikido, right?