... And we all know how it ended up for her....Kassandra in Murkmire counts?
All those nobles you've mentioned are not nobles within their traditional Argonian tribal societies, though, yes, they are some sorts of outside of Argonia. The Argonians have still been at their pre-feudal primitive communism level of socio-economic development. It is one of the most primitive societies in terms of socio-economic formations. Nobles usually step on the stage later, when economical basis changes and thus it urges the social structure to change too either to the next stage of a chattel slavery state or an early feudal one. So their maximum at this point is a first among equals instead of a noble.
That's precisely what OP was going for, though: "not high ranking Argonians within Argonian culture, but Argonians found in positions of wealth and power outside of it".
Veezara wrote:"Once, I was a Shadowscale. An assassin in service to the King of Black Marsh. Trained by the Dark Brotherhood since the day of my hatching. Ah, but that was a lifetime ago. Today, I am the last of my kind. My order is extinct. Now, I happily serve Astrid, and this Sanctuary. I am a trained killer, and once again have been given purpose. Life is good."