I don't think there is any bio-mechanical or mechanical advantage to drop bars that are wider than one's shoulders.

The most comfortable drop bars I have ridden were the Randonneur type, which sweep slightly upward from the stem, and have drops that flair slightly outward.

If you ride on the drops, it's good to be able to wrap several fingers around the brake levers. On one my bikes, the geometry of the handlebars and the brake levers made this very awkward.