Rizzi has that coach O or even Dan Campbell feel. There's no downside to hiring him. If the season goes to pieces like it did for the Raiders interim turned HC he'll be gone in a year and you'll have a cleaner cap, and better draft position to reset.
There's only upside w/ Rizzi. In a way he's cleaner than Weaver, Glenn, Kafka, and Brady in that there's no projection on how he handles the HC duties. The 8 game audition shed light into that already. The other options you just don't know.