Yes, there’s no such thing as a sure thing in hiring a head coach. Even Harbaugh struggled at Michigan, and had to take a pay cut.
This was in spite of the fact that Harbaugh had success as a quarterback in college and in the pros, then paid his coaching dues in college and the pros before getting progressively larger head coaching gigs.
Harbaugh was head coach of three different teams for over a decade before landing at Michigan, almost flaming out, and finally finding the QB who could let his team compete at the highest level. Moore has nothing remotely similar on his resume. Hopefully the national championship, and maybe the ripple effect of Saban’s retirement, helps him land some five star recruits to build around. But this is a big big job for any head coach, let alone a first timer.