Actually, what you said does make sense. I kinda felt like someone was going to say somethig about that. But I mean, I still feel kinda iffy on the consistency of the SCS, mainly because reality is always a little different than the theory.
My concern is, when using the SCS, the shape of the actual surface that makes contact with the bb is different than the shape of the SCS. I doubt that the SCS can make a perfect shape with the bb (right now, we're talking about a bucking with no bump or nub inside), since there's a good amount of variables, like the thickness of the bucking and the amount of hop applied. The thicker the bucking is, and the more hop applied, the bucking becomes less concave and more of a flat shape. However, an H nub pushes down on the bucking in a more direct way with all of the hop focused on two points, so the bucking is more likely to retain a shape with two points of contact, regardless of thickness or hop amount.
Then again, this argument is all just as theoretical as the argument for SCS's over H nubs. Maybe in reality, the two are equally consistent and effective! It's something that would be really hard to discern, since I doubt that the difference is really significant at all.