The only thing those statistics show is what has happened in the past. They only show a correlation. They do not show a causation. That's why they can not reasonably be used as any indication or prediction of future outcomes.
The outcomes of complex systems involving human beings, like NFL teams and seasons, can not be accurately predicted by relying historical statistics of performance of other complex systems. It's not just complicated, it's complex with too many variables.
The reason is because people are slinging it around as real gold when it's fool's gold and people have fallen for it. Just look at how many teams have lost games, because they went for it on fourth down instead of kicking a FG or punting. Look at the teams that lost games, because they went for 2 earlier in the game instead of 1.
Now that more teams are starting to go for it on fourth more often, it's failing more. Sample size is important. It's irrational to compare the success rates of a significantly smaller sample size to a larger one and weight them equally. If the analytics saying go for it on 4th were any kind of a "scientific" indicator or predictor, then one would expect all teams to have fairly close success rates. They don't. Some teams do a lot better or worse than other teams.
This all started with modern astrophysics and space exploration. The universe is a very complicated system, but it's not that complex. Except for in very rare circumstances, the principles of physics don't change which means all non-living bits and pieces of the universe act in consistent and predictable ways. Astrophysicists learned a lot about the universe relatively fast by gathering extensive data and thoroughly analyzing it for patterns that lead to deeper understanding and predictive models of the universe.
Scientists in other fields of study did the same thing. An NFL team is a very complex system. How the individual parts of the system, the people, are going to react and interact with each other is inconsistent which makes the system unpredictable. People like predictable. Unpredictable makes them very nervous and uncomfortable. That lead toward people fooling themselves into believing that they can predict human behavior if they just get enough statistics and analytics.
The objective truth is that there is no way to know how any of these coaches would do if the Saints hired them. There's no way of knowing which coach would get the Saints the closest to winning a Super Bowl. Some people are really uncomfortable with the unknown, which leads them to convince themselves they know which coach would end up getting the Saints to closest to winning the Super Bowl.