You make some valid points. Some of these were brought up by @CoachHayes on his Canes YouTube channel. Hayes was a grad assistant for Mario at FIU.
Coach Hayes said that what scares him about Mario is thst he's never been an offensive or defensive coordinator. Therefore, he's 100% reliant on getting good offensive and defensive coordinators. If your team is successful, you'll have to replace both coordinators every 2-3 years which means you have to get lucky with coordinators every 3 years. So, basically Mario would be Ed Orgeron who got lucky with his OC, DC, and QB Joe Burrows in order to be at that championship level. Orgeron needed to get lucky twice when his OC and DC left and didn't strike lightning resulting in his firing. Now you see his DC killing it as a HC at Baylor which Joe Arranda would be high on my list if he'dconsiderleaving Baylor.
Coach Hayes stressed the importance of being an OC or a DC in your background. He pointed out Nick Saban's model of success. Because his teams are so successful, Saban has to replace both OC and DC every 2-3 years when they get HC jobs. Saban is a defensive guy with a ton of experience as a DC. For his offense, his entire offensive staff are seasoned former head coaches that were also OCs. He can replace anyone on the offense because there is so much experience in the room that it doesn't disrupt the offense. Coach Hayes points out that Saban's new DC is a young DC from the University of Texas-San Antonio (UTSA). Why did Saban choose this young guy with little experience NOT even at a P5 school? He chose him because he wanted someone he could mold and tell what to do. He doesn't have to fight with his DC because Saban is the expert on that side and would bump heads with a seasoned DC. Saban's system makes the transition easier when he loses both OC and DC. When you've never been an OC or DC, what is your team's identity? You are basically Ed Orgeron completely relying on getting lucky hiring both your OC and DC in which you have to get lucky every 2-3 years on both sides of the ball.
The successful model is to be a top OC or DC and hire someone you can mold on your side of the ball. On the opposite side of the ball, hire as many seasoned coaches so you can plug and play with more seasoned experience when someone leaves.
Mario has no OC or DC experience and certainly none to be his calling card and that's what's scary.
I do believe Mario would fix 2 major problems and eliminate a 3rd.
First if all, he would fix the country club culture and make the team tough.
Secondly, he would have the offensive line performing at a consistent high level.
Thirdly, he would solidify top 5 to top 10 recruiting classes every year.
Those 3 things would put Miami in the ACC championship game every year and I'm more than good with that as we would win our share of ACC titles and make the CFP on a consistent basis perhaps winning a national championship once again.
I truly believe we have the play makers in the program to win a national championship. We need a culture change and to sure up the trenches and LB & CB.