I would like the OP to give one example of a martial art style that is difficult to translate to MMA, along with the rule or rules that inhibit this translation. Also, how should the rules be changed to include this particular martial art?
OP did include a video of someone talking about how Judo isn't represented in MMA, certainly not in the medal stand. Which I think is false, because Ronda Rousey was one of the most prolific women's MMA fighters, and came in with a strong Judo background.
Judo is probably underrepresented (compared to wrestling and BJJ) because of the lack of gi in MMA. To fix this particular "problem", adding a "Gi MMA" would make a lot of sense. I do believe there are some BJJ competitions that move in this direction a bit (but that doesn't help UFC). A gi in most arts is just a uniform, but in BJJ and Judo is part of the sport as well. Like how a football helmet isn't just part of the uniform, it serves a practical use in the sport.
Some other arts I could think of that aren't represented as much include self-defense focused arts like Krav Maga and Hapkido. I'll use Hapkido as an example here. Most of my Hapkido techniques would be against the rules in MMA, because we attack the weakest part of your body we can get ahold of. 90% of the time, it means we're grabbing fingers, and using those to create a gooseneck on your wrist that will control your arm and the rest of your body. It gets much more difficult if I have to grab your wrist, because I have a worse grip and much less leverage that way. However, rules are there for safety, and relaxing rules creates a greater risk of injury.
Then there's arts like Taekwondo and Karate, where typically striking is for points instead of for knockout. A way to make them fit better is to go away from the 9-10 scores that they currently use, and instead use a point system like Taekwondo uses. (Yes, I singled Taekwondo out, because I believe Karate pauses after each point is scored). There is precedent for this in combat sports. Both BJJ and wrestling do this.
However, because of how complex MMA is, I'm not sure that you could have an objective scoring system that is fair for both strikers and grapplers. Something like:
- 1 Point: Punches, elbows, knees, leg kicks, recovering position in grappling
- 2 Points: Body kicks, spinning arm strikes, advancing position in grappling, sweep or reversal in grappling
- 3 Points: Head kicks, spinning kicks, submission threats, jumping position in grappling
Priority could still be given to KO or tapping your opponent out, but in this way a point-based art could start to fill in the gaps. Additionally, it might incentivize people from Karate or Taekwondo to compete in MMA, if it offers options closer to their style of fighting.
To sum up, the three ideas I have to "fix" the "problem" with the UFC. I'm not saying they wouldn't come with their own problems, but these are ways to get other arts more involved.
- Add a Judo/BJJ Gi, so there is something for Judo and Gi-BJJ guys to grab onto
- Reduce the list of banned techniques, so that self-defense guys can go for the moves they want to
- Change the scoring metrics to reward every landed strike, instead of being a subjective 9-10 score, to encourage point-based striking arts to join the fray