[SuperSajuuk]

I noticed that you can actually apply to be a gladiator on the website, as well as a contestant. They must be banking on a few not returning then.

Could be that, or they just want to have a larger pool of Gladiators, to avoid the situation with the Edge where it was just the same 3 gladiators (6 in total: 3 men, 3 women) being used on rotation, and probably to just have the options in case any of them get injured. Since the run of episodes looks like it will be the same as the first one, they likely don't want a situation developing where they end up not having enough Gladiators by the end.