No, it's never good enough, because it's flat-out wrong. This statement:
> Air over the top has to travel farther in the same amount of time
is not true. The air on top does not travel farther in the same amount of time. The air slows down and travels a shorter distance in the same amount of time.
It's only "good enough for a classroom of children" in the same way that storks delivering babies is—i.e., if you're content to simply lie rather than bothering to tell the truth.
> Air over the top has to travel farther in the same amount of time
is not true. The air on top does not travel farther in the same amount of time. The air slows down and travels a shorter distance in the same amount of time.
It's only "good enough for a classroom of children" in the same way that storks delivering babies is—i.e., if you're content to simply lie rather than bothering to tell the truth.