추공 (Chugong)
It doesnt make sense that 3 people couldnt cover their surrounding with eyes. Humans have Field of View around 120degree. So if 3 of them stood back to back and watched, they should be able to cover all 360 degrees. Although that Field of View might not be perfect 120degrees, but stone statues are usually big. So they should not be able to slip through those mini 1-2 degrees blind spots.