Never really thought about how many specifically. As many as the plot demands there to be until a specific number becomes relevant, in which case I'll probably choose an arbitrary number based on the scale of the arena.
New arrivals get stuck wherever there's room. Our characters got lucky and ended up with a pretty decent first experience. Most aren't so lucky. It's not expected for new entrees to live long at all, especially if they go solo. If you go in as a team, it is expected you'll live longer, so you get a nicer start. But generally you are treated as disposable trash and just stuck wherever is most convenient at the time.
New arrivals get stuck wherever there's room. Our characters got lucky and ended up with a pretty decent first experience. Most aren't so lucky. It's not expected for new entrees to live long at all, especially if they go solo. If you go in as a team, it is expected you'll live longer, so you get a nicer start. But generally you are treated as disposable trash and just stuck wherever is most convenient at the time.