Johnson coach is a catch wrestling trained and one of the best martial arts coach in the world. Jones only been defeated by himself. He just started training in a gi last year sometime.
Jon jones, Demetrius Johnson are white belts technically. There is no perfect system. Every martial art has strong and weak points. Just focus on getting better overall and learn as much as you can.
It is not the style, but how you are trained by the teacher. Boxing,kickboxing(sanshou, muay Thai, savate, Burmese kickboxing, Dutch kickboxing),judo, sambo,catch wrestling, Brazilian jiu-jitsu,wrestling, etc are all sport and will get you ready for fair or unfair unarmed fighting. Karate...