The "we're too dangerous to fight" is an easy meme to propagate. But let me just ask you this: let's just say, hypothetically, that your theory ("maximum damage" masters are "useless in MMA fights") was false. How would you ever know? Assuming that someone did not yet have a belief about that proposition, what kind of evidence are you actually aware of, about whether the statement is true or false?

Military application of the "maximum damage" martial art, and the restriction of certain training to military personnel, would be solid evidence that it goes beyond what is considered safe in sport.

For instance, I know that certain weapon techniques in Krav Maga are generally taught only to policemen or combat soldiers.