I don't agree that it's the power scale. I have played Amber reakinned with all sorts of stuff. supers, Fables, Star Wars, Pirates.
The key is to pick games where there is antagonistic relationship between players.
So Pirates was based on Black Sails. We had Stats of Leadership, Combat, Prowess, Guile. We had no powers but did have some core skills, l - Seamanship, Statecraft and a bunch of resource heavy options with allies, followers ships, political contacts etc .
I think any game in which the players want their characters to be the best at a list of things and in fact hich there is plot intrigue and deceit is perfect.
I clarified about relative power scale. Are you familiar with the
Paranoia RPG? It has a lot of antagonism between PCs, as they are all secretly traitors but are rules by the Computer. I don't think it's a good fit for diceless, though, because part of the feel of Paranoia is being a helpless pawn. Random and wacky results are part of the feel.
Amber PCs have reliable abilities. (Unreliable would be randomness.) If you win a fight, it is by innate superiority or guile.
So plot intrigue, guile, and winning by strategy are part of the feel. That means that the PCs should feel like they're in control of their fate, not at the mercy of unreliable or random variations. Feeling in control of your fate is about having some mastery over your circumstances.
Does that make sense?
I just ran a 19th-century-esque fantasy game with psychic powers using diceless stats of Charm, Mind, Spirit, and Body. The PCs competed mostly with other psychics in the face of a huge invasion.
Asking about your games -- When you ran pirates, did the pirates feel like their ship might just go down in a storm? Or were they not concerned about that sort of random events, and felt more like masters of the sea - threatened mainly by other masters of the sea?