Well the only thing i could commend TN for doing is giving jann the some classic Bruce Lee getups from alot of his movies instead of the old try and true yellow jump suit all the time. Trust me if you see alot of Hong Action flicks like me you would know the difference.
Were not talking about mannerisms or clothing choices, were talking about styles of combat here, Jann Lee uses JKD emphasis on that, Kiryu is just a street fighter at the end of the day.
Yessir with some karate, wrestling and mma moves thrown in his ever evolving fighting style. You should look up how JKD was formed maybe that might give you a little bit more insight on the fighting style since some of JKDs punches were from boxing, the kicks like fencing (sword fencing) and he the law somersault aka flip kick from enter the dragon.
That was mainly my point XD, if you say you do JKD that means you have knowledge in multiple martial arts, not just one, so, in a sense, Kiryu is also a JKD fighter, since he even has trained in Philipine and Chinese martial arts.