Benchmarking your sales team as a whole allows you to look outside your company and how other firms are practicing sales, and it also emphasizes the point that your sales team is all on one ship -- the ship that is your business. Where they steer that ship (and whether it stays afloat or starts sinking) is ultimately up to their efforts as a group.
For example, we all know that sometimes there is a personality mismatch between a given prospect and a particular salesperson. Do your sales staff hand opportunities off to a colleague when these situations arise? Are lead generation efforts and insights shared across the group? Are problems that arise in one part of the sales department discussed by the team in the context of continuous improvement.