re: If Orgeron is capable of fixing the downfall after 2019, why didn’t he prevent them?

Your logic is extremely flawed. One, he might not have known the problem existed until it manifested itself during the season. Think defense and Pelini. Two, he might have known of a problem but had no control over it. For example, the mass migration that took place after the championship season. And three, it happens.
Orgeron has shown the ability to identify a problem and fix it. Remember after the Bama game three years ago. He recognized the offense was a problem and went out and fixed it. To the extent that we had possibly the greatest offensive production in the history of college football.