that's the ESTP actually
but dunno, I don't think I've met an ENFJ at least not close enough
in theory, we have a "contrary" relationship which is okay 1-1 but gets unbalanced if in group, I'm guessing due to group dynamics and the INFP possibly deharmonizing the group and the ENFJ trying to harmonize it back and creating conflict
I thought it was supposed to be like "perfect" the same priorities, just with the judger and perceiver difference.
Hmm... I know my INFP husband would benefit from a ENFJ friend in his life. I know this sounds funny, but a perfect couples friendship for us would be if I found a INFJ friend (female) and she was married to a ENFJ. lol.
For me I get a lot out of the INFJ-ENFP relationship. I find it to be quite powerful for me-- like fuels my personal growth quite a bit. So I do actively look for INFJ friends and find them very meaningful and delightful.
My INTP sister is married to a ENTJ--- this works absolutely so well for them. A great pairing.
So.... all that stuff in theory is supposed to be very good.
I think what he is saying is the ENFJ (Fe, Ni, Se, Ti) and INFP (Fi, Ne, Si, Te) has the same function order but the opposite direction for introversion/extroversion.
On to the topoc...
The hypothesis likely stems from Fe and Fi. Meaning the Fi user will teach the Fe user how to be "selfish" and not seek so much external validation. The Fe user teaches the Fi user how to be more "flexible" in their values as in it's not the end of the world if your values are crossed because the other person has deep held values. Having different functions would mean their is a potential for "growth" for both individuals in the relationship. This "Growth" is likely what is supposed to be the connection, that you grow separately as individuals but ultimately grow together as a unit.
That being said...I think it's a bunch of poppycock. There is a reason that Fe and Fi clash and I think a more realistic thing happening is the Fe user trying to live by the Fi user values (even if they don't agree with them) but do not want to have a conflict. Conflict with an Fi user is unavoidable and Fe doms TEND to dislike it. I'm not saying it's impossible BUT there is no denying it would be A LOT of work for both parties involved...