Can we add to the FAQ that you can't compare two martial arts or fighting style by watching two people fight - because you're only comparing the skills of the respective fighters (and possibly the wisdom of their coach in preparing them for this particular fight)?
I think the problem would be solved by requiring "context" be included in the question...
Have the FAQ some how guide people to ask about fighting in a clear context: "which art is better in a cage fight?" (commenters would probably pester for specific cage rules/systems) "which art is better for short people defending against people with knives?"
Questions with enough context can be answered objectively.
There are objective answers to some questions.
If fighters of style Y lose to fighters of style Y 99 times out of 100, we can stop saying it's about individuals. Yes, as David Hume argues, past performance is no indicator of future success. Yes, cage fights aren't back alleys. But it's silly to discount the wealth of knowledge we have about inter-style competition, and it's silly to totally discount the results of no-holds-barred competitions. It is often very possible to say that in the general case, style X turns people into fighters better than style Y.
I would be very opposed to such a silly addition to the FAQ, and further, I don't see how it belongs. The only purpose I see would be to use it as a pseudo-authoritative cudgel against people you disagree with. That has nothing to do with quality of posts on MA.SE.