I will outline why TaeKwondo, no matter contact level, or even rules, breaks down in a Muay Thai ring against a skilled Thaistylist. This despite the fact that all strikes in Muay Thai are also in TaeKwondo! My reasons may surprise you.
1. Footwork. TKDoins are often renowned for their speedy and light footwork. However, being light on your feet in a Thaiboxing ring also carries the disadvantage of being easier to knock OFF your feet. Thaiboxers in comparision are more flat footed but rock solid to the ground. Getting put on your butt repeatedly will wear and tear on you. And this will happen even more easily with one foot up in the air kicking..
2. The kicks. This ties in to the point above. TaeKwondo kicks are snappy and quick of the feet, but makes one liable to get pushed off balance in a rule set in which you can actually grabb and push down kicks. Stability will once again be a major question mark. This is demoralising in the long run and, the kicks you perfected in the dojang won't get you as many points (or KO'S) as you might have previously though..
3. The hands. To break a skilled Muay Thai fighters defence in the ring you will need to soften him/her up with boxing, and/ or have a boxing defence to punches. Kicking alone will not get the job done against a legit guy(especially not concidering 1 and 2). TKD guys are not drilled in either offense or defence to the level required.
4. No clinch. This can be modified in theory, but I will list it here given that most clubs neglect it.
5. Lack of Continious fighting. TKD is geared towards one strike, one victory philosophy. Even WTF rules that allow full contact break after making contact. It will be an adjustment for a TKD fighter simply fight on and is definately puts him/her in a slight psychological disadvantage, compared to the thaifighter.
Feel free to comment and disagree on any of the points!
1. Thai footwork is not as rock solid as you seem to think it is. It is very balanced in motion, but always very light on the front foot. This backweighted stance is great for checking kicks, but poor for movement and is also a little unstable. Thai fighters knock eachother around quite a bit actually.
TKD footwork is far beyond MT in mobility and distance control. This is the main strength and it is pretty effective against MT. At long range TKD dominates.
Both footwork styles have their strengths and requirements.
MT-nerves/legs of steel. TKD-agility and stamina for days.
2. The main strength in the kicking style is the fast, non-telegraphic, linear nature of tkd kicking. And tkd practitioners are very used to people trying to kick them in this manner and get very good at avoiding them. High level tkd sees every MT kick from a mile away and has the footwork to avoid it.
TKD fighters are also generally very skilled in landing and avoiding headkicks.
Basically TKD's non telegraphic and extremely fast kicks are difficult for other styles to see coming and deal with.
3. The hands are a toss up. They can be trained to a high level in either system. I've seen fighters in both styles have incredible boxing skills.
The main difference is the guard and tactics. Again TKD/Shotokan striking thrives long range. The main defenses for punching are parries and footwork/movement. Where as MT goes with a high guard/cover. Good for deflection and elbow delivery, but harder to use sophisticated hand strikes.
4. No striking art can touch Muay Thai's clinch game. This is the heart of Thai Boxing to me. The unique flavor
5. I already made a point on this in another post, but there are always natural breaks in a match. Be it TKD, MT, Boxing. There is distance finding and chesswork in each discipline.
This is what I have found to be true in my personal experience