The Abridged Book Of Ninja Fighting

In Season 3 of Mighty Morphin, the Power Rangers get new power coins that draw the power of NINJA! This means they get cool ninja suits and cool ninja powers. Yeah, that's awesome, right?

But isn't the ninja supposed to be a stealthy figure?

In the old days, ninjas were spies and assassins who would use stealth to get in, do their thing, and get out without anyone noticing. The art of invincibility, as it were. It was a thing with the Ninja Turtles whenever they needed to do something stealthy; they went in, did their thing, and got out without anyone noticing. Not just because of their appearance differing from the humans, but because they were NINJA. That's what they're supposed to do; it's what they were trained to do. Sometimes, they make noise, but for the most part, they're supposed to stay in the shadows and they usually do that.

So why is it that whenever we have Ninja Rangers, they're out in the open and not doing anything that is remotely ninja-y? They make loud noises, they taunt, they don't do anything remotely stealthy, they have ninja magic... but they don't use stealth or anything. What kind of ninjas are they?

The ones that apparently study from the Abridged Book Of Ninja Fighting.