NPs on average need to admit having worse habits than NJs on average. It's like, having lots of N is already a problem, and having no leading extroverted judging function makes it even greater problem. SPs are a bit sloppy too, but their leading S takes better care of such things overall.
Now, about INFJ / ENTP in general - they can sometimes even be mistaken for each other. (similarly INTJ and ENFP) That's because such relation shares primary function (N), if we don't count direction, and shares the top extroverted judging function - Fe, for INFJ and ENTP.
So both INFJ and ENTP are primary N-types with Fe.
Similarly, both INTJ and ENFP are primary N-types with Te.
This Fe or Te part is important, because this is mostly the way they look on the surface. Judgement is how actions and expressions are carried out. And the extroverted part of it is what gets seen.
The easiest way to differentiate ENTP and INFJ is by how serious and strong willed they are (Se vs Si). If they are "heavy", as character, more likely they are INFJ; if they are "light", more likely they are ENTP.
But it gets harder to guess, because INFJ may be in temporary light ESTP mode, and ENTP may be in temporary serious ISFJ mode. It takes some practical skills to recognize which is which, but it's not too difficult. The NJ seriousness is stronger, and the SP gregariousness is wilder; the NP lightness is truly fragile, and the SJ decisiveness is narrow-minded.