in reality, shouldn't two of the same class/aspect be able to be in a session as long as they aren't the exact same role? like say a Thief of Mind and a Thief of Void, since they don't serve the same purpose within the session. hell, two of the same God Tier could be able to be in the same session if one is a positive player of the role and the other is a negative/antagonistic one. that works in any other game with a class-based RPG system, so why not SBURB?

We don’t know if it’s impossible for repeat classes and aspects in a session.  But we also don’t know if it’s possible so it might be.  It’s never been touched upon in canon and I don’t know if Hussie ever revealed the answer in his old formspring Q&A’s