your missing the point, take the ten best shihans ,and ten best fighters in the world. dream on if you want to.
OK, I set the rules: None, but the only tool is a live blade (katana).
Could be interesting, but I guess all the shihan would survive.
8 because choose, not to enter as they neither want to kill or to be killed. And two might enter, but probably your 2 best mma fighters will would withdraw.
Then all 20 survived. What is your view on that result?