Cutting to the chase, Ryan Tannehill is 89/138 with 4 TD and 3 INT when throwing against two high safety looks (cover-2, cover-4, and man-2). Compare that with 24 TD and 6 INT on 182/285 (per Sports Info Solutions) against single high (cover-1 and cover-3) and you’ll see that the Titans thrive against single safety looks.
Against the Ravens in November, Tannehill was 14/23 for 198 yards, two touchdowns and an interception against single high looks. Two high? 4/8 for 39 yards. 3.4 yards per attempt. Adding a second safety takes the explosiveness out of the Titans passing game, which relies on in-breaking routes and space from their explosive receivers, particularly when operating out of 12 or 21 personnel.