I feel your pain, limpets are really useless, shooting the drives out on ships is pretty bad as well. It's only useful against players who try to flee.
That said, one time I managed to get lucky and kill an npc type 9s drives while it was barely moving. Too bad it was only carrying a mid range cargo, 4k a ton I think. I managed to follow behind it scooping and play catch up when it got too far away. All in all I stole 80 tons. Best haul from an npc ever. I've never been able to replicate it however. We need harpoon and cables, ala star wars: empire strikes back.
We need a plunger on a rope.