The "too good to be true" sense is definitely similar to what Ni doms do, except to you, it's still this vague hunch that something is wrong. To an Ni dom, it's obvious that something is wrong.
A recent example: a friend was talking about the Mythbusters episode that covered the bees lifting the laptop. https://www.youtube.com/watch?v=_12L_Dme8Vc
is the original video. I watched this video and immediately knew it was fake. But it would take hours for me to explain HOW I knew it was fake, because there are years of experience with physics involved. Those years of experience develop an "intuition" of what is possible with physics. I understand concepts like lift, airflow, fluid dynamics, thermodynamics, chaotic processes and so on. All of these taken together convince me that the video is fake, the primary indicator being that there is no way that the laptop would hover so precisely. Forces have to be exactly
in balance for that to work, or there has to be a credible dynamic equilibrium with a feedback mechanism to make it work. Drones and helicopters and harrier jets have a huge amount of engineering behind them to make them hover precisely.
But to most other people without that expertise, the best they might get is a feeling of "too good to be true".
Now, Ni does not equal "expertise" per se. Other types can be equally expert with engineering to spot the problem here. This is just an analogy to give you an idea of what it feels like. If you have enough knowledge, you "just know" it's fake, but the knowledge is so esoteric that you can't just way why you know without confusing everyone around you. This is how Ni feels.
The Ni strength is being good like this with just about any complex system, given a fairly short time to study and understand it, because Ni naturally looks for the key functional components that might dictate failure or success. That's just what it does, without having to try very hard, just as Ti doms can just do logic in their heads without trying too hard, or Fi doms can read an individual's emotional state without trying too hard, or Si doms can recite their knowledge of a topic verbatim without trying too hard. But none of these introverted dominants can explain HOW they do what they do very easily. They just DO IT.