First, I do not believe in the arrangement of the cognitive processes. I only believe in the arrangement of the first two (e.g., Ne and Ti or vice versa). I don't necessarily believe that Fe or Si should be the third or fourth, necessarily.
In tests, I do score as having a high Fi, near balanced with Ti, and I don't think my Si or Fe are stronger than my Fi, so that already puts the arrangement theory in question.
Not to mention that the definition of the E/I duality in psychology differs from the conventional usage. And MBTI has not clearly stated where it stands in the duality.
Though in my personal experience, I consider hardcore, very Ti-dominant INTPs to be those archetypes acting as intellectual posers on the web, seemingly nothing else on their lives that is going for them, while the mature ENTPs have somehow evolved from that, having more character flexibilty, and thus haviung the less need to throw their Ti around.
As much as possible I don't wanna define things based on how much a theory defines it.