Look, I'm not sold on Beamer, and I actually don't like defending Ray's decision making on any level, but It's not like Shane was a football ops guy. Being a recruiting coordinator (in addition to his position coaching duties) is a huge thing and incredibly important job. Especially when expertise related to high-level recruiting is essential for a power 5 head coach. And Lincoln Riley doesn't pull the guy from UGA and give him the assistant head coach title unless he thinks the dude is going to help the team. Riley could have hired anyone - he chose Shane. And the AHC isn't just a title, it comes with tons of responsibilities. Head coach responsibilities that he's trusted with so it frees up the head coach. I would say he was as qualified to be a head coach as any assistant coach out there at the time (including sitting coordinators - because coordinator experience is immaterial unless you're calling the plays for your new team).
Again, who knows who will win at USC - Beamer may still be that guy (if he fires Satterfield). But it's not like Chadwell is some unicorn candidate. His success is nice - but has he ever recruited and signed a 4-star player at any point in his career? It's a different world in the Power 5. And wins are great - but does anyone know what kind of guy he is in the media, with boosters, athletic department staff, etc? That's probably 40% of the job for a head coach (and why a guy like Harsin was destined to fail).
I'm hearing that Chadwell is the front-runner for Georgia Tech, so maybe we'll get to see what he's capable of soon - though I've been campaigning for years to stop considering the ACC as a power conference.