Mike Leach teams take a while to get going. Yes, they beat LSU but (almost) everyone does that in 2020. Part of that is the install: Leach famously throws it every down and runs a super simple offense based on being really, really good at a few things and bludgeoning you with speed and repetition. The other part is that he only takes over terrible teams in remote corners of the college football universe. My point: if you have to play Mike Leach, Year 1 is a good time to do it.
Missouri, as a program, has had a great deal of success against Leach, to boot.