Knows multiple defensive strategies
Coach Smith may have been the Rock of Gibraltar over the course of his career, but he has proven to be remarkably adept at learning and deploying an array of defensive strategies through the defensive lines and eventually outside linebackers that he has coached.
in 2012, the Buffalo Bills converted from an odd-man front (3-4) to an even-man front (4-3), and Coach Smith was the focal point of that conversion. While this is not an attempt to cry wolf over the likelihood of the Rams' defense's imminent conversion to a 4-3 base defense, it does illustrate that Giff Smith understands and can execute the basic tenets of both.
To emphasize that point, in 2014, the Tennessee Titans converted their defense from an even-man front to an odd-man front. Coach Giff Smith was the focal point of that conversion, as he was the Titans DL Coach that year as well. As you can see, Smith has been the positional coach who was tasked with converting between 3-4 or 4-3 defenses going in either direction.
Perhaps you are not overly impressed with that robust knowledge of both 3-4 and 4-3 base defenses. But I can assure you that when it comes to whiteboarding the defensive strategy for the next opponent, that knowledge will prove to be quite useful. It's a simple matter to flex a defensive front to launch four pass rushers on any given play, and that strategy needs a defensive mind who understands the gap assignments for that type of response.
While not a know-it-all by any means, he does come with the expertise that is highly respected in football circles. It's true that many teams wanted to add Giff Smith's expertise to their own coaching staff. But it was LA Rams HC Sean McVay who was able to convince him to remain in Los Angeles, California, and simply agree to join the LA Rams coaching staff.