Morris' worst run was 2009-2016. This was his worst run by far and it included 2 Super Regionals, 4 Regionals and 1 Omaha appearance (probably 2). Consequently, one needs to find coaches that have performed better than Morris during that stretch. What coaches over this time period made Omaha once, made 2 Super Regionals and 4 Regionals?
The hockey-gnome will argue that 1 Championship is markedly better than the entire body of work, but even using that criteria Morris remains top-10 during that period of time. [This time period ignores the fact that Morris is one of a select few that have won Omaha more than once.]
One could award 4-points to winning Omaha, 3-points for reaching it, 2-points for the Super Regional and one for a Regional. For Miami, the streak is highly important, so you cannot assign a value of zero to making the tournament. If you want to assign an 8 to winning Omaha, a 3 to making it and 2 & 1 for the latter choices, then that would be passable. Even then, the guy is top-10.
Even during Morris' darkest stretch 2009-2014, Morris remains a top-10 coach under all criteria. During this stretch, EVERY team that Miami lost to in the post-season made Omaha. Even Stony Brook, who later beat LSU in the Super Regionals.