Let's play connect the dots. Yes UT played 3 of the top 6 scoring offenses in the country.. They also played 5 in the bottom 35. Statistics aren't based upon 3 games, they actually use every game.
Cincy went from 94th to 8th in total defense under him. Most people would find that impressive. Obviously you don't.
As for his recruiting that you have questioned, today it shows his 2022 LB recruits at 4, 5, 13, and 19. So 4 out of the top 19. Yes, he personally recruited them (he's a former linebacker). To put it into better perspective, Alabama, Georgia, and Ohio St each have two.
So his coaching and recruiting is a "reach" to you. I and most can see why ND hired him. (That doesn't mean he will be successful). Just connecting the dots looks like it may be a decent hire. Like Coach Heupel his players love him and probably got him the job. That also says something.