Yet again, it's not like Karate(derived from Okinawan origin) doesn't have TDD. It's only the watered down American incomplete versions u all r use to that don't. This nonsense "mixing" myth is purely an American fantasy because you're use 2 such poor quality MA. There are legit lineage teachers that immigrated to the States that teach the complete systems, but they're not marketing machines like the Gracie's and because of their 8 to 10 years Uchidechi live in student training tend to draw the dedicated and in many cases will still only teach those who show them elevated potential. They pick their students, rather than "mixed" MMA schools who will take money from anyone to teach their elementary level "style" too.
So no it's not mixed, it's seeing whole complete systems regain their original forms. Take Judo, Kano Sensei south out and was taught Tenjin Shin'yo-ryu Jujitsu and after his teacher died was passed the official lineage qualification(Something Americans have zero knowledge about). He went on to train more "mixed" forms of Jujitsu before founding the Kodokan where he brought other lineage arts into his Kano Ju Jitsu(KJJ)
the original forms of Jujitsu splintered into in today's terms. Throws Judo, Ground fighting, BJJ Wrist locks Weapons Disarming, Aiki JJ, Aikido, Striking, Okinawan Kempo(and other forms), Shotokan.
If any of those modern arts drill TDD they are practicing an element of their original form, not "mixing" as clueless Americans have been lulled into stupidly believing.
MMA has solidified it's "form" Boxing, MT, BJJ, Wrestling. That's what trainers, commentators and fighters have been saying for over 10 years. If u train the simplified version of those sports you are a "mixed" martial artist. If you have formal ranking in a legit lineage Martial Art, and train some MMA you are training the specific ruleset focused area of MMA. Not watering down that legit Martial Art.
Get it, or r u 2 dumb to understand beyond what the pay per view shouts @ u?