The ninja is clearly op, now if that is the intended meta and the balance team way working, sure... It's ok.

But deny that the ninja is op is just irrealistic and biased either just to play devils advocate because you nothing better to do or work for the company, or because you are owner of the unit and you don't want to see it nerfed, because you paid money and it makes you happy to win that way....
Either way when you can put the kit of 3 or 4 different ninjas, entire teams skills, and they all combined can't do what 1 unit does,it's a huge flag that proper balance is needed...

If that's ok for the devs and the players is all good.
But to be an hypocrite and say it's just fine put a tank against a motorcicle, that's just lying and call people dumb.

Hope I don't offend any susceptibilitys but it is what is.