The same functions are in use albeit a bit flipped around. As a result the differences between the two are rather nuanced.
Extraverted Thinking (Te) in the dominant position is characterized by a tendency towards segmentation, organization, systematizing, and a desire to understand the external world.
Ti as a function, is the most logical of all. Te by contrast, is the most rational. While logic is founded upon axioms, driven forward by static principles, rationality is characterized by general pragmatism. Te is a tool used to guide action and solve problems based upon the empirical aspects of the world, hence it’s frequent association with the sciences and business. Due to it’s empirical nature, it is not moved by emotional arguments, or even pure logic. It emphasizes hard evidence, and in the absence of that, literal testing or verification.
In the dominant slot Te also creates an overwhelming desire to control the external world. To the ENTJ, being made subject to the whims and conditions of the empirical world or even external individuals, is intolerable. One could view their desire to master it as a pre-requisite to dominating it (a la’ Napoleon, Julius Caesar, Mao Tse-Tung, and the plethora of ENTJ CEOs.)
When paired with Ni, it has a tendency towards reformation, although this frequently resembles the usurpation of power or overthrowing of established systems. The Ni factor causes it to prize effectiveness over efficiency, noting that one can be highly efficient at something that ultimately yields poor results. To the SJs, this type resembles a bringer of chaos, every decision and action however has been carefully deliberated upon, the likely effects shrewdly calculated. Nothing is ever left to chance.
Introverted Intuition (Ni) in the dominant positionis characterized by an unconscious processing that precedes reason, frequently manifesting as insight or foresight.
The processing of Ni is unconscious. Due to that the typical Ni dominant experiences the majority of their “thinking” as fantasy, subjective imagery, or the conjuring of symbolic devices. From these constructs emerge sudden realizations that come paired with a conviction of things to come, or a sense of having tapped a hidden truth.
Ni also engages in a form of meta-perspectivism, noting objects and the interpretations that they most commonly warrant. Those interpretations are perceived as projections trying to elicit very specific thoughts or actions. The attitude of Ni however, is to contradict and ultimately exploit those projections.
A good example of that being parasites that have learned to give off the same pheromones as ant larvae. The ants perceive the pheromones (objects) as coming from an infant (interpretation) telling them to bring it food (the elicited thought and action.) The ants end up feeding the parasites even after they’ve grow to ten times the normal size of a larva, never stopping to question what they’re doing.
The meta-perspectivism of Ni combined with the empiricism and systematizing of Te, creates a penchant for masterminding or “gaming the system.”
For ENTJ, Ni plays a supporting role to their Te. They are primarily unaware of it and experience it as visceral instinct, or vague direction pointing that allows them to forsee obstacles and to predict actions. Their intuition is primarily used to point out such things and to guide the offensive-mindedness of their Te, as a result their strategies typically center around preemptive striking and blitzkrieg-ing.
Due to having Se in the tertiary position, ENTJs are typically less patient than their INTJ cousins, prone to taking immediate action and responding the moment a problem or threat emerges. That lack of patience and tendency to not strategize far enough into the future has the potential to bring about ruin (reference the itchy trigger finger of Napoleon, or foolhardy actions that lead to the assassination of Caesar)
However, they are far more in touch with the concrete world and less fearful of it, creating a solid balance between the abstract and literal. Between Te-Ni-Se, action and planning occur at once, moving dynamically in the present with their minds always 3 steps ahead. When time is taken to develop Ni, they improve strategically, able to patiently plan further into the future and avoid the silly mistake of shooting before aiming, or trying to do both at once.
For INTJ Te plays a supporting role to their Ni.Whatever is conjured up by their intuition, is automatically assumed to be valid and they set their Te to work thereafter. This occasionally becomes the equivalent to demanding alchemy of a chemist, although this is sometimes a virtue, considering the scientific and technological achievements of the type. But such ad hoc thinking can be detrimental to say the least, creating models and strategies that fall apart upon being applied to the real world. As such, time has to be taken to develop Se.
Se in the inferior position creates a fear of the external world, hence INTJs are inclined to control it much like the ENTJ, but with it lower in the stack, INTJs are also very patient. That patience tends to either make or break them, sometimes causing the type to utterly miss windows of opportunity or to wait for so long that their strategies are no longer applicable.
When the proper balance between Ni-Te-Se is found, the type maximizes it’s strategic abilities, playing their rivals like chess pieces. A case in point being Hannibal Barca, his enemies left with the sensation of having been struck down by the heavens themselves.
When these types take the time to cover their weak points they begin to temporarily work out of the others primary strength. In certain contexts they can resemble the other so far as personality traits; ENTJs resembling INTJs in the lab setting; INTJs resembling ENTJs in management.
That can be further skewed by enneagram.
Type 3 and 8 INTJs can seem very ENTJ-like.
Type 5 and 6 ENTJs can seem very INTJ-like.