Why would you do that rather than just having a SG that's a good defender. If your shooting guard can't defend the perimeter he doesn't have much utility.
A "respectable" outside defense guard CAN defend on the perimeter in D4, which was the original question of the poster. If he's supported by other guards by higher skills and positioned well in the defense, you'll do fine in D4. You might even have your league's top defense, like I do. In this case, the guy's my top scorer, so I cut him a little slack.
(6820817)As I said before, you can't have all the skills you want in your early seasons.