Das mit den Verträgen mit Elementaren wurde auch in den Ask-The-Devs Lorefragen erklärt:
Could you please explain the lore behind goblin shamans? Goblins do not seem like a particularly spiritual race, especially one that would care about the elements (as evidenced by the Venture Co.).
Goblin shamanare an extension of their society’s single-minded devotion to making a profit; to a goblin shaman, elementals are potential customers. Goblins do tend to be a bit more forceful in their negotiations than the other shamanic races (especially the tauren) would like, though they are far less forceful than what we’ve seen from the taunka in Northrend. (Unless the elemental tries to weasel out of its contract. Elementals tend not to have breakable knees, so goblins sometimes have to resort to other methods of control.) As for the goblins’ „mechanical“ totems, note that these are merely physical manifestations of the small totems they tinker/craft to form a link with the elemental spirits. Instead of lugging around large totems, goblin shaman have a ring (probably the same ring on which they keep their house and motorbike keys) with small totems they’ve built as conduits for the elemental spirits they do business with.
https://wowpedia.fandom.com/wiki/Ask_CDev