Tim, one of the most talented man at playing a bad guy safely ever. Very skilled at the FAST armored suit defense stuff, scenario design, debriefing, all that jazz.
Terry, relatively small, but for quite a while the highest paid bouncer in a hot region, and well paid for a damn good reason.
Clint, who has walked on the dark side pretty thoroughly. He prefers vampires to his acquaintances. His acquaintances are both scarier and real.
(There were others-- love ya, Law Dawg and if this flies and we put together one that includes Sims, you'll need to take some time off work to teach gun stuff...)
What Your Sensei Never Told You:
The law. The differences between sparring, brawling, fighting and killing. Real bad guys. Improvised weapons (Clint got me thinking about them at a new level and I teach environmental fighting). Stress decision making. Intuition training. Slamming and jamming. Chaos management. Hell, probably even relevant first aid and definitely justification and articulation.
Just a three day course, an exposure to high-end violence. Mental, physical, spiritual.