Not all position coaches are meant to be coordinators. Not all coordinators are meant to be head coaches. It’s okay to be a really good position coach but not a good coordinator. There’s a reason GP was demoted rather quickly at his previous stop. And a reason you never saw his name linked with other OC openings (let alone NFL jobs).
If he can’t design an offense or just can’t figure out how to call a game, that’s okay. Move him back to TE coach where he excels and hire someone who does know how to do it. Bring in someone that can design proper route combos, understands motion and play action, and knows how to call a game.
I can’t think of another coordinator that magically became worlds better in less than a year. Genuinely, if someone has examples, I’m all ears.
If MF is staking his ND HC career on GP then so be it. If next season is similar to this one, they both can go.