In the literature entry for The Lord of the Rings, the note about the Paths of the Dead being a zig-zag isn't actually right. It's not any faster as a route to Minas Tirith, but Aragorn wasn't going directly there. What Aragorn needed to do instead was intercept the Corsair fleet, and the only way to do that meant crossing the mountains. As far as crossing the mountains is concerned, the Paths of the Dead is indeed the grandmother of all shortcuts.
In the literature entry for The Lord of the Rings, the note about the Paths of the Dead being a zig-zag isn't actually right. It's not any faster as a route to Minas Tirith, but Aragorn wasn't going directly there. What Aragorn needed to do instead was intercept the Corsair fleet, and the only way to do that meant crossing the mountains. As far as crossing the mountains is concerned, the Paths of the Dead is indeed the grandmother of all shortcuts.