Cooter isn't really from the Indy orbit, it's a Sirianni connection. They were together in KC in 2012 and he was on the staff here in 2021.
Now that a week has passed and I've had time to think on it, I understand why Lurie would hesitate to clean house. There's justifiable reasons to make the move, but firing a coach after three straight playoff berths and a SB appearance is jarring and hard to justify to future candidates no matter what. Despite the "only 32 of these in the world" mantra and a roster that's clearly ready to win now, any candidate would have no choice but to be apprehensive vs a rebuild scenario and longer leash elsewhere. So between that and the players having his back like they did it's not a position you want to be in so I get why Lurie is trying to give Nick a chance to right the ship.