This discussion may contain spoilers!
So I was watching a play through of 400 Days and Russel said something about the group he was with that went like "There was a guy with a daughter about my age..." Couldn't that be Carlos and Sarah? Also he mentioned a teacher and his wife were in the group maybe Alvin and Rebecca? It would make sense because of what Carlos said in the preview for episode 2 when he mentioned that he was in a group before the group he's in now. Also They did say that Carver was the leader while Russel said Steve, but doesn't Carver sound more like a last name? So maybe his full name is Steve Carver? And don't forget Sarah looks a lot older than Clem so she could be about Russel's age. I think maybe after Russel left, Carlos, Sarah, Alvin, and Rebecca got fed up and left like Russel did. Maybe that's also why Carver's group hates Carlos' group for leaving. Just a theory I'd like to hear what you guys think
Edit: or maybe Carver is a nickname like the Governor and his real name is Steve idk :P