I think the monk-specific outfits in Pathfinder Kingmaker look super cool, and there's nothing in the game that says or implies that your character is a literal monk. You are whatever you think you are. I made a dual nunchaku wielding aasimar monk Bruce Lee just for the heck of it, then realized that character looked just like God Fist Lee Sin. It was hilarious. If I only had Shadowless Kick, that would have been perfect. I stopped that playthrough though, to switch to a Knife Master because a sneaky slippery backstabber is my true calling.