The numbers don't really match your premise.
Mizzou is shooting more free throws this year, 22.3 per game compared to 19.7. They're making essentially the same number of FTs per game: 15.4 this year, compared to 15.4 last year.
So they're clearly shooting a worse rate: 69.3% compared to 78.0 % last year.
What's the difference? Mainly two guys: Tilmon and Brown are down significantly from last year in terms of FT percentage. All the other regulars are about the same or better.
Dru Smith is down slightly but still shooting 83 percent.
Pinson's percentage is nearly identical to last year at 81.8 percent. Very good.
Pickett, Mark Smith, Mitchell Smith are all much better this year compared to last year.