Good. While Balthazar has come to terms with the proper Castiel, no need to make him go through it with another.

Anyway. "It's not practical for me to go everywhere with Claudia--ignoring that I can't get in the Warehouse--which is why I needed him. Crowley noticed her, so I wanted someone no one would be looking for. He'd been given instructions to keep an eye on her from a distance--along with the warning that the Winchesters taught her that rock salt fired from a shotgun trick."