Not all young coaches have a rolodex (for the lack of a more modern term) of assistants on standby. I assume we'll either hire a guy like Vrabel, who will have some guys he can turn to, or a very young coach getting his first shot. That type of coach, especially if he were a defensive minded coach, might think Kubiak and his crew are a better option than what he has access too.
Nevertheless, it's a secondary discussion. the bigger point was that I don't think Rizzi lands the top job because we feel the need to move away from a holdover at the top of the coaching organization.