To get good rep in Tormenta for nades i suggest stand near the digging spot. There are 3 target around there (always Seabeard/Urchinfist/Mollusk). Kill all the Seabeards and Urchinfists until all 3 are Mollusks then use hex shot one by one till their voodoo drained. Remember not to leave one drained Mollusk unattacked for too long (they will wake up).
Move around and they will follow us like puppies until all three stand close to each other. Now they are ready for our grenades.