This sounds like it can work and it might, but the time that I tried it people were annoyed. They joined the game to play wizards. They weren't at all pleased with waiting several weeks to do it.
I actually had some success with a "let's learn how to play everything but the magic" mechanics using a bunch of grogs and companions. The saga "officially" started in canon 1220, so I had this adventure in the Levant in 1218, where the companions and grogs, on crusade, end up in conflict with a lone maga over an ancient ossuary. Hermetic magic, ghosts, demons, and medieval land warfare were all involved. The adventure ended in a way that made it reasonable that the companions and grogs, once back in Germany, would be the kind of people who would partner with magi.
Well, I'm not at all sure I should have offered the players the chance to start a new covenant.
I've been advised that it's the number one mistake newbie Storytellers make and the campaign I wrote the questionaire for did nothing to disprove this. There were probably lots of factors including the limitations of play by chat.
But if I were doing it again I'd say: if you're going to start afresh you're a long, long way from civilisation so we don't have to worry about interacting with mundanes or other magi until you're well set up. And if you want to interact with other magi and mundanes you're going to have to take being the new bugs in an established covenant. Politics and covenant construction can be done together but it would make life simpler to separate them.