I'm a bit NOOB in pokemon in comparison with people here in smogon so I don't know if I'm a good adviser...That said, mmm...let me think.
My first BT was also bassed on Ninjask BPing SD and Speed boosts but it didn't work very well (probably I was not playing it well by that time). Mamos is a though pokemon and w/ a priority move but it has too many weaknesses (5) in my opinion. I would prefer torather use a steel pokemon instead. Do you plan to use Gengar as a revenge kill? Do you use destiny bond? I mean, if Mamos has taken out 2/3 pokes and ninkask is still alive you could just go for DB to end it.
In any case, I've read that TRICK teams are the best in the BT (that's why I'm trying one now lol). A yawn lead also works well.
How long is your best streak? How is the team working so far? :D GL!!! :D
PS: Sorry if my recommendations sound silly...as I said, I'm not a pokemon master like everybody else here :P