I don't think you'd have the time to, say, be a magus (eg study, teach an apprentice, go to Tribunal, etc) and handle being a noble (eg managing the lands, carousing at the court, handling internal affairs, lots and lots of mundane stuff). I just don't believe one would have the time to do both. If you want the resources, you can go at it from another direction, for example the wealthy virtue.
The Hermetic Oath
prevents you from taking any Oath to an overlord as well.
The Wealthy Virtue is also dependent on Social Status.
As a Wealthy , Landed Noble ,
you can always have a steward.
You also do not have to be the primary heir.
Yes , more suitable to a Companion.
However , it does give your ST a default Story Flaw ,
either Major or Minor.
Is a life as a Magister in Artibus even desirable for a magus? Being eight years older at one's gauntlet because of the time spent at university, plus having to spend two seasons each year teaching in public: to me that looks like a Major Flaw for a magus. Even if it were possible (it is not!), being Wealthy cuts that only down to one season teaching per year - and then you had already used up two major Virtues.
The scholar Jerbiton character IMO better is built around Educated, Skilled Parens and perhaps Apple Gild Training.
The noble-born Jerbiton - instead of violating his Oath of Hermes by pledging allegiance and taking his place in the feudal pyramid - could be distinguished by Temporal Influence, Privileged Upbringing and/or Social Contacts.
IMCs storyguide characters could of course be Jerbiton and Magister or Noble and Wealthy to boot at the same time, with all the attached problems of living double lives. But I'd rather protect player's characters from that hassle.
Magister in Artibus isn't an appropriate socal status for a magus. A magus is a magus that is its own social position. If you want your magus to have the education give him the virtues and age that he needs to have to aquire the education. If you want your magus to teach have him teach.
If you have a Jerbiton who is a noble give him contacts, reputations and the like to make him a noble. Just don't take the noble social status because your character isn't just a noble they're also a magus and the noble social status isn't really where they belong.
Don't cry that your character concept is screwed, that's simply not true. Even if it wasn't simple to create a magister in artibus without making up new virtues, are you telling me that you wouldn't make up a new virtue to fit your character?
Are you sure that you're not complaining for the sheer joy of complaining rather than because you have an actual complaint?