Do the Vigilants of Stendarr hunt down Orcs as part of their quest of persecution, since Orcs view Malacath as their patron?

I'm genuinely curious, as I see no mention of it in the game thus far. If the issue is addressed in some way in game, I'd be grateful if anyone could point me there. In any case, I despise those guys as meddlesome pricks.

Another user in a different topic reported seeing a Vigilant of Stendarr and Orc confrontation outside one of the cities, though I cannot remember which one. They said the Vigilant cut the three Orcs to pieces in seconds...

Would not have predicted that! I'd like to see more confrontations like that in game. I don't see why the Daedra tolerate the Vigilants of Stendarr, though I wouldn't be surprised to find out that they themselves are Daedric pawns.