If these setpiece generators become tags, then they would have to be limited in multiplayer. A tag could only be picked by one player. You couldn't have two Merchant players reach the same trigger for a setpiece.
There's nothing stopping the game from suspending your disbelief and allowing all 4 individual rogues to be THE rogue for the purpose of a quest.
For example: You get to remove all 4 collars as "The One" if you use the "open 4 clients and give all characters to yourself" way of having a custom party.
Custom characters of each race will also have their own unique Origin stuff, and you can have a party of 4 humans in multiplayer.
Aside from the negligible minutiae of how things are written, there is literally no practical reason to treat origin characters any better than the custom made ones.
The effort that went into the origin stories could have been better used making the tags feel more relevant and/or having more of them.
I'd gladly have a 'merchant' aspiration instead of Ifan as a thing at all.
