Dean.
I think that they'd be better off in teams. If something comes along that one of them can't handle, at least they'll have someone there to watch their backs.
I heard that Buffy was doing some training with some of the people staying inside the building. I think that'll help them with everything. It certainly won't make them experts; only experience'll do that. That's the biggest thing that I'm worried about. They sometimes seem too confident about all of this. Yeah, they've battled demons and fought off apocalypses in their worlds...but this isn't their world. They don't know every rule. They don't know how everything works, you know? And I worry that someday something is gonna catch up with them that they can't beat.