Nope, I don't think you did? Depending on the idea you were going for, though. If you're just going for the whole thing as this being like a 'test' things suggested seem to be fine. If you're wanting a little more that'd be the idea of them dropping different 'enemies' and such in now and then. E.g, somewhat 'evolved' zombies, mutant animals and people, rogue groups and such?
I believe everyone is? Lakota only made a new character, I'm not sure if the others are wanting to add or get rid of any of their characters, though.