What makes knight so great with mentor? Accessing tabernacle? Maze of ith? Both? Or just having a bigger body? Sorry if the answer if very obvious, but mentor still seems a solid menace against knight (but I agree that does not seem as frightening by any means).
Yes, Tabernacle is real. Denying any mana before hand is just a cherry on top. A lot of the time, you will have a sphere out(thalia), chalice, abolisher, eidolon--SOME sort of disruption to hurt your opponents play. Being one turn behind knight is a massive beating, because then you are eating wastelands, or letting any utility lands resolve. They need to have swords on hand immediately to remove Knight.
You also need to remember, Mentor is what makes the deck go round. If they don't have him (there's only 4!) the deck is not nearly as threatening. In fact, I would still say Pyromancer is more of a threat than Mentor, just because they can start getting a few tokens rolling a turn earlier. 2 v 3 is big vs us. We need Knight as well, only a 3 of, to really beat up the tokens.
I miss orzhov pontiff, maybe I will bring him back as a 1 of as well.