That's a great link. Anyone who has been to the Combat Trauma class has learned the importance of wearing plates and avoiding the extremely high percentage of fatalities that come from damage to that part of the body.
The guy in the bottom pic is a Marine wearing an OTV. His plates aren't improper, it's an illusion made my the style of the carrier. His plates are exactly where the guy's are above him. Find the jugular notch and measure down to the top of the carrier on both; almost the same distance.