I'm not trying to be mean or nasty,but its ninjutsu,not ninjitsu. I plan to train in muay thai as well as ninjutsu.Bjj doesn't really appeal to me,a friend of mine has his own school in winter park and teaches it,but everytime we spar he can never put me down,i can always counter his attacks and subdue him. Why,won't ninjutsu be a big help if you don't mind me asking?
Wow, that's impressive. A BJJ instructor can't take you down, and you can counter ad subdue him? Awesome. Any art that can get your grappling to your level will be "accepted." The beauty of MMA is that all comers are welcome. COULD a brawler, or someone compeltely self taught off Youtube videos be champ? SURE! As long as you don't break the rules of wherever you are fighting, it's all good. We haven't seen any primarily Ninjustu fighters at a high level yet, but we could! It just so happens that in the recent past Muay Thai, Wrestling, and BJJ have been the main arts that the champs and high level guys have excelled at.
If Ninjutsu works for you (which it clearly does!) I'd say go for it, as people will not be prepared for your style.
Best of luck!