@wish12oz... Your probably right...I don't follow the math of the game nor use a parse to "break it down". The "SATA" idea was just a filler term to describe an new ninja ability to boost a throw effectiveness. Just how effective? Well that's debatable and someone with the math behind it could possibly fix my intent.
If as u say a ninja lose 6 rounds or swings or something like that, this new ability should at the very least match either total damage average or as you say give enough TP back to cover the loss over rounds.
As far as the shriuken argument, yes it's valid that stars and darts are very lacking and/or expensive. That's not to say that a possible fix is ninja darts that feature (3) darts throw at the same time. This could be a new type of multi-throw item(think star with double or triple attack).
Lets have some fun, what about a new "Utsemi:San" Ninjitsu, that creates a set of clones 2-3, that causes the next attack to do triple damage...think Naruto and the "shadow clone Jutsu. This wouldn't benefit your dual wield, necessarily only the first strike, but could increase either throw or regular Ninjitsu? With a sufficient recast timer or say 5min or so, wouldn't overly abused.