Okay, here we go.
There is one thing that Jack Flak has a point on -- many introverted judging types are no less judgers than their extroverted brethren, and on with perceivers, despite being 'perceiving' primaries, and so on with perceivers. Because of this, for intents and purposes of this thread, I'm going to call the top two functions that Judgers have (Fe, Te, Ni, Si) 'judging' functions and the top two functions Perceivers have (Fi, Ti, Ne, Se) 'perceiving' functions, even though they're not called such in everything else. This is because there is a peculiar way that judgers think and perceivers think but are linked to both traditionally called 'judging' and 'perceiving' functions.
So here, judging means 'wants closure' and perceiving means 'wants open-endedness'
I hope I haven't confused you enough yet.
So, what we have is our continuum of introversion to extroversion below:
<Extreme Extroversion ----- Extroversion ---- Ambiversion ----- Introversion ----- Extreme Introversion>
The origin is Ambiversion. You do not fall on that point.
So each person, and each function, falls on some point on the spectrum. N can be either 'extroverted' or 'introverted' and to some extent. The more extreme, the more particular it is to i or e of the function as prescribed by MBTI.
Also, the 'order' of functions is fluid, and depends on the person. The shorthand for the functions to work with are in the MBTI type codes that you already have.
Here are some variations for a common type code on these forums, INTP.
Ti Ne Si
This is your garden variety INTP, 'normal' among what MBTI describes. However, not all INTPs have to be like this to still be considered INTPs. These are some variations that aren't quite this, but still do not fit any other type:
Ti Si Fe
An INTP who highly favors introversion. Any extroversion is handled not by choice, so it falls onto something the INTP does not prefer, Fe. This INTP may also look like a judger because two functions are 'judging' rather than just one. The difference, though, is the use of Ti, far to the 'introversion' side, matching closely how 'Ti' is described in MBTI, especially in its differences to Te.
Ti Te Ne
An INTP who highly favors their dominant function. Because of this, the first function's 'attitude' is not so fixed, though they do favor the introvert half of the spectrum. May seem a little like a judger, because a judging function comes earlier in the order, but is more 'perceiver-like' than the highly introverted INTP.
Ti Ne Fe
An INTP whose 'introversion' or '3rd function' has been discouraged. Still seems much like a perceiver, but more 'involved' than a typical introvert.
And then there are lots and lots more. The whole thing can be very dynamic but one thing that always remains the same would be dominant function, and the attitude of the second and third function (What differentiates an INTP from an ISTP is that one prefers Ne/Si and the other prefers Se/Ni).
S, N, T, and F may fall close to the center and be proficient in both sides but will, the vast majority of the time, prefer one or the other.
Anyway, theory done. The point is, just because somebody settles on one type code (INTP, for example), doesn't mean they're exactly Ti, Ne, Si. Profiles can be misleading because that's what they describe rather than any variation. They don't allow for any room to wiggle.
Not all INTPs, or any type, for that matter, are built the same. You can't go by the stereotypes enforced by the profiles.
But, of course, you knew that already.