Japanese Jujitsu is filled with tons of different styles. These schools includes weapons training, strikes, and joint locks. Brazillian Jujitsu is simply a Submission grappling/wrestling style. The style of Japanese Jujitsu the Brazillians learned was Judo. Though at the time it was still widely called Kano’s Jujitsu. Kano removed the more dangerous techniques and the weapon defense to fit a more modern Japan. His new style of Jujitsu destroyed the others with ease. That’s why it was adopted by the Japanese police. Due to the fact BJJ is essentially Brazillian Judo, it’s gonna destroy traditional Japanese Jujitsu no problem.
Danzan-ryū Jujitsu
This is another style of jujitsu that is very much Judo. The problem is you can’t be sure if the school will spar. Which automatically puts it below Judo and BJJ. Even if the techniques are legit, without realistic sparring you can’t expect to be good at fighting. This is also a huge problem with Tradtional Japanese Jujitsu schools. Most of them only understand the forms, not the actual combat applications.