I don't agree. If I'm wrong, please show me the error of my ways.
If you connect the edge of the doors to the edge of guard with a flat surface, then measure from where that surface intersects the plane of the blade out to the edge, that's the exposure. If the razor is place on the face so the edge of the doors and the guard touch the skin, and there is no pressure, in theory, this plane is where the skin will be. The distance the blade extends beyond that place will determine how much contact there is between the blade and the skin, i.e. the aggressiveness. The angle of contact also plays a role, so the curvature of the door surface will effect aggressiveness too.
All else being equal, retracting the edge of the doors SHOULD increase contact between the edge and the skin. I think the position of the guard has a greater effect on exposure than the position of the doors. That's how they can get away with the scalloped edge on the doors. And, I'm sure they position the guard so this is still a mild shaver, even though there is lots of blade visible.
Imagine grinding off one edge of a cap on a three piece and smoothing the resulting corner on the top surface. I'm pretty sure the shorter side of the cap will be more aggressive.
Hmm... I'll see if I have a junker three piece I can modify to see if this is right.
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