Only one Philip Rivers-esque Bengals signing makes perfect sense

Cincinnati Bengals v Tennessee TItans | Kevin Sabitus/GettyImagesThe Cincinnati Bengals don't often think outside the box when it comes to improving their roster by any means possible. They usually take a reactive, not proactive stance to such personnel decisions.

Credit where it's due: When Joe Burrow got injured earlier this season, they waited a while, but ultimately pulled the trigger on a Joe Flacco trade. Before suffering a sprained AC joint in his throwing shoulder, and even for a brief bit thereafter, Flacco played some of the best ball of his career.

Obviously, it didn't mean much, since Cincinnati's defense kept letting him down. Despite Burrow coming back, the Bengals' playoff…