I was in the Judo National Team in France . I competed for 10 year. French National Champ and European Champ. Then I competed in Jiu-Jitsu Fighting System. It's kind of judo and karate. I was the 3-time World Champion so I have a kickboxing background.
The rules are karate rules. You have 3 rounds. Round 1 is kick and punch like karate. Round 2 is judo. Round 3 is ground fighting. You have to be good at all of them. They way you finish the match is to get ippon in all of them.
Yes, he was a good judo player. He was supposed to fight in the Olympic Games in Munich but he couldn't compete because Benin , the country I am originally from, didn't pay the fees. He was ready but they didn't pay.
You can train. Nobody can come into your dojo and say don't do that. The main federation in France is the Judo Federation. If a new martial art comes, they ask the Judo Federation if it's good or not. And they just look at judo. If it's something else, forget it. I come from judo, though. Then I did jiu-jitsu. I tell them what I'm doing and they know me and know I'm serious.