Being that I am a bit short on time at the moment, I am only going to reply to the training part of my argument. In the combat training that I am talking about, you CAN get killed in the training and people have died. Therefore it is realistic. Specifically I am talking about advanced military training, either recon marines, SEAL, Special Forces or any folks of other nationalities who do this type of stuff. Now I am not familiar with the statistics of SWAT live fire room clearing training but I would bet that someone has died in it also. Remember people have died also in martial arts training. I can think of examples in both Iaido and jujutsu. SO, death is always just around the corner in our training. It is up to us to perceive that danger, if we dont we are meat for evolution. We just have a tendency to forget this in the "tender and peaceful" art of aikido. A little later I will blow out my opinion on combat variables.