Structure and predictability is J, has nothing to do with S or N. Js prefer their lives to be controlled and predictable, Ps prefer being whimsical and spontaneous. Do some research.
Sigh. This is why many type experts--Nardi/Behrens/Haas/Hartzler to name a few, won't teach type preference by preference.
Type dynamics is the term used to describe the way the four letters of a type code add up to more than each individual component. In other words, every "J" type has something in common with the other J types but still is unique because of the other three letters in the code and how they interact
Judging and Perceiving actually refer to one's preference in interacting with the external world, with Judging types preferring to come to Judgment or closure, and Perceiving types preferring to stay open.
However, within the 4 NJ types, the two Introverted types are actually dominant Perceiving types. Their preference for staying open resides in their internal world, so they may show a more decisive lifestyle to the external world but still prefer openness. It can actually be quite the source of inner conflict
Because Intuition is about creativity and novelty, most N's dislike externally imposed structures. This includes NJs. Speaking for the INJs, we never look at our job descriptions, frequently go off plan when new ideas catch our interest, think through contingencies so we can be spontaneous, and march to the tune of their own drummer. Actually a lot of our routines allow for spontaneity in areas that really count for us.
Openness and closure are very different from predictability vs. whimsicality.
Some type practitioners go so far as to say we shouldn't teach about J and P at all, because it leads to such stereotyping. People often resonate with J's wanting to be in control--of coming to closure or producing product such as a decision or a term paper or a task. P's then want to stay open as long as possible--hold ideas in tension, explore other avenues, wait to see what works best at the time. But again the IPs are actually dominant Judging types and may lock into certain routines and structures far more readily than the INJs...
In other words, when it's taught properly the J-P dichotomy provides insights into how to get along, at least in the very J cultures of most American companies and education systems...
If I am not wrong 4 NJ types are the most rare 4 type.
Think of it as cosmic wisdom since we know what's best for the rest of you and therefore can get annoying...
There is a "large" difference between NFJ and NTJ.
INFJs and INTJs have the same dominant functions and can often operate like twin sons of different mothers if they have a common cause. The INFJ tends to be a bit more "Trust me, it'll work" and if there's mutual respect benefits greatly from the INTJ's ability to think through flaws in advance or guess what questions others will ask. The INTJ benefits from the INFJ's insights into how to get buy-in from everyone for their plans.
ENTJs and ENFJs have opposite dominant functions and naturally gravitate toward leadership so yes, they may fail to find common ground. If they agree on goals, though, just fall in step. they'll combine forces to strategically organize the heck out of whatever they're trying to do.
All NJs are insane, take this as a first and second hand account.
Thank God we're so rare.
Also we're the easiest to annoy and the hardest to piss off. Forget T-F differences, we have ideas of what really matters, and the only way to genuinely get an NJ angry is to get in the way of that idea. Whether it be based on people or concepts.