If there were more Knights of the Round, who would you think they'd be?

I know that it's said not all seats are filled everytime, but if they were, I'm thinking there'd be a tournament to judge proper candidates for the roles which, depending on the setting, I think could be filled by Orpheus Zevon, Oldrin Zevon, Shin Hyuga Shaing, and Dasko la Clermont alongside the canonical members. At least that's my gut feeling.