Tennessee Titans quarterback Ryan Tannehill says their offense is trending in the right direction.The Buffalo Bills’ defense will be the ultimate judge of that when the teams meet on Monday night in Nashville, Tenn.Tennessee (3-2) owns a comfortable two-game lead in the putrid AFC South thanks largely to NFL rushing leader Derrick Henry, who has rushed for 640 yards and is aiming for his fifth consecutive 100-yard game.But the Titans remain a work in progress. No team has allowed more sacks than their 20, and their receiving corps isn’t close to being at full strength. Julio Jones has just returned to practice after missing two games with a hamstring injury and A.J. Brown isn’t yet at 100 percent, although he played last week despite a hamstring problem.Now Tennessee faces a defense that leads the NFL in fewest points allowed per game (12.8), yards allowed per game (251.8) and takeaways (15). An offense some thought could be the equal of 1980s Air Coryell or the 2000s Greatest Show on Turf will have to tighten things up to avoid the fate of Buffalo’s last four opponents, two of whom have been blanked.”They do just about everything well,” Tannehill said. “You see them getting after the quarterback, see them solid in the run game, tight coverage on the back end, great in the red zone, great on third down. Really just an all-around solid defense.”And the Bills’ offense is no fun to deal with, either. After a shaky first two games, Josh Allen has gone back to the form he flashed in 2020, when he was perhaps the NFL’s top breakout player. Allen threw for 315 yards and three touchdowns in a 38-20 romp at Kansas City in Week 5.Buffalo (4-1) leads the league in scoring at 34.4 ppg while ranking fifth in rushing (140.4) and eighth in total yardage (410.4). Devin Singletary, Allen and Zack Moss give the team a potent rushing attack, while the addition of Emmanuel Sanders and the emergence of tight end Dawson Knox as a big-play threat in the passing game have only made the Bills even more dangerous.