Hi,
Thanks for the interest in the article. I think the source of the confusion is that the article you read: "A Leg to Stand on" is part of an ongoing series on the development of the rules and fighting methods associated with mixed-martial arts sport fighting. The term (Mixed Martial Arts) has been in use since the early 90's, but it is a contraction of the much older "mixed-match martial arts" which refers to a match between two different martial arts (usually as part of a pro-wrestling show, either shoot or worked). "Mixed-martial arts" (or Mixed Martial Arts) as a contraction of the older term, was first used by Howard Rosenberg of the LA times (or perhaps his editor) in 1993. The term has come to be used as a synonym for "hybrid martial art", but that is really a misnomer, as it is used almost exclusively to refer to hybrid
combat sports. There are innumerable hybrid martial arts, from Kujukembo to Jeet Kune Do, but they are not relevant to the activity referred to as "Mixed Martial Arts", which can mean either the sanctioned format of the sport, or the type of fighting methods popular for contesting a match in the sport (same is true for the sport of Boxing, and the fighting method used to win matches, also called 'Boxing').
The series discusses how the format and the fighting methods of Mixed Martial Arts came to be... in this case, how elements of Thai Boxing spread to countries with strong grappling traditions (Japan and Brazil) where they were available for combination with Brazilian Jiu-jitsu and Shootwrestling respectively. Mentions of the various victories (and losses) of Muaythai against other fighting styles are there to tell the story of how the outside world came to adopt elements of the Thai fighting style. Certainly they are relatively effective techniques, otherwise there would be no interest in learning them. Often it was those defeated by a Muaythai fighter who saw the value in learning the foreign style; many of the matches I mention i the piece were won by the foreign fighter (four, I think).
The article prior to this one is viewable at:
http://mixedmartialartshistory.wordpress.com/2013/02/20/ronin/ and covers the spread of Osaka newaza to the same two countries (Japan and Brazil) via Judo, Brazilian Jiu-Jitsu and Catch Wrestling. Essentially each article is a segment of the relevant history of martial arts, as it pertains to a particular fighting sport.
I hope that clears up any confusion.