For auditions, specific spots open up and are filled as they are needed and the appropriate player found. If I auditioned for a last stand spot in the very back of the section that's because that's all that is available and open. If I win, no matter how good or how much better I was, that's all I'd be oferred. If a second chair position opens up, the section doesn't generally move up nor do they re-audition a whole section to figure out hierarchical seating based on ability when they get a new member. Personally, last chair is my favorite spot because there isn't much decision making. I just show up, shut up, listen, and play. Like being the bassist or violone player in a baroque ensemble. Just sit back and let the other viol sections argue about bowings, style, musicality, etc. Then when they come to a consensus just listen and do that. I'm not really in this for the money. I just prefer the level and quality of working together and performing a professional group tends to have.