And I don’t want any cop-out answers like “Oh these guys are pacifists cause they make others do the fighting for them”, I mean a genuine faction of people with power, who reject war, even when it’s convenient for them to do war, and even when going to war would be considered the right thing to do by the masses, out of a genuine principle of pacifism. How do you make those people seem like a convincing faction?
Look into the nomadic peoples of arabia who gained power through trade. They aren’t a perfect example because they did engage in violence but this could easily be adapted. Petra is also a very cool city you could look into, it was heavily fortified by its natural surroundings and therefore easily defensible in a way that minimizes harm.
I think your best option is a highly religious sect of nomadic traders for a number a reasons. The religion gives a source of their non-violent philosophy, trade gives them economic power with the least possible violence, and being nomadic makes it difficult to take this power from them through violent means.
Self Defense would be acceptable right? It would fit with the religious order thing if they were highly trained in some non lethal combat.
It’s up to OP really but yes imo. Pure pacifism to the extent of accepting death is idealism