the highest win totals for top two teams in a division
In 1999 the 13-3 Titans finished 2nd to the 14-2 Jags in the AFC Central. The Jags only two losses were to the Titans. The Jags also lost the AFCCG to the Titans, then the Titans ultimately lost the SB at the 1 yard line against the Rams.
Jim Harbaugh went 13-3, 11-4-1 (lost SB), 12-4, and then 8-8 and was fired (or maybe quit, but either way lost the power battle with Baalke)