I personally like the idea of altered shots when SB comes into play. It does tie in with RL instances on the court.
However, SB remains more of an Inside skill rather than an Outside one. This is because when you are guarding someone on the outside, you tend to give him a bigger 'leash' or keep him a specific distance from you. The closer you get to the rim, the more this distance reduces and when you're under the basket, you're literally side by side. The shorter the leash is, the bigger impact SB will have on altering the shots.
I feel this brings another dimension to defences, and not dependent on one skill.