and that were true, i'd never want that kind of HC here in the first place, because my HC was hired to believe a leader of men, and his self confident, presence and assertion stands out
over the entire team, and is infectious through the organization. If anything asst. coaches become HC's elsewhere, as you see with Belichek, Andy Reid, McVay, Parcell, Jimmie Johnson, etc.
Is Sean Payton gonna be afraid to hire on a Dennis Allen as DC of the Saints because he used to be an ex-HC ?
Is Sean McVey gonna now be scared of his own hired DC Brandon Stalen because he's a young up & comer and soon HC himself ?
Is Pete Carroll gonna be scared off of a Dan Quinn or Gus Bradley because he hired them on his staff?
is Andy Reid gonna be scared off himself because he has excellent assistants such as Eric Bienemy and former assistant Mike Nagy ?
if anything comes close to your predicament, and though he's more of a retainment than outside hire, I could see even Kellen Moore taking over the reigns of
new HC in a year, McCarthy himself doesn't supplant himself next year as the undisputed, unquestioned leader of this team in a winning path.