Another way to understand it is through the classic temperament blends.
NT is Choleric in the area of leadership and action. This means they have a sort of aggressiveness (I.e. "Pragmatic") as well as an independence from submission to others. The Interaction Style (social area) tells us the other temperament blended with Choleric. ENP is Sanguine. So ENTP is. SanChlor, and this is said to be the most rambunctious and competitive of all the blends. The INTP is less so because of the introversion, of course. They're less "expressive".
While the NTP's are "informative" or people-focused, socially, the NTJ's are directive, or task-focused, and hence don't come across as argumentative as NTP's; as debating is relating to people.