Vengeance dh best covenant

I use Bis function for generic vengeance dh character and it recommends me to go night fae
Is this a random choice or it’s actually the best covenant for vengeance dh?

The generic characters are representative of a reasonably well-optimized character, but might not be the absolute best. They are meant as a good starting point if you don’t have a character of your own to load.

Our guide pages can give you a rough idea of how the covenants stack up in different scenarios.

I play havoc dh. I was in Venthyr but based on AMR’s recommendation to play Night Fae switched. I can say without exaggeration, or gear change that the addition of Night Fae’s powers to the rotation boosted my dps. That said, I know Vengence dh is played as tank - but my experience tells me, and lots of amr simulation, that the recommendation is probably correct.