For networked roots such as those of crab grass or ground covers, the angular attack may more effectively entangle a larger section of the root system than a vertical attack . Simply approach the soil from a slant towards an area where the roots may be clustered. Because of the terrain, sometimes it's difficult to get close enough to a weed for a standard vertical attack . There may be shrubs that encumber a vertical attack on a sheltered weed. The torpedo attack requires a little more thought to determine the depth at which you wish to attack the root from your location.
Some weeds have very shallow roots and others have deep roots.
Try to aim the torpedo towards a mid-point of the root system. If you grasp the weeds in the coil firmly with the free hand, a quick, forceful yank can efficiently remove the weeds from the coil. The more quickly you yank in a snapping motion, the less strength needs to be applied. It's speed vs. strength. The number of weeds in the coil and the type of roots involved are factors that may affect the success of the yanking effort.