Are you sure that's right? I'm pretty new to the lore but that doesn't sound right to me. Are you sure your not mixing up Elementals and Sprites? Everything I've seen in questing about the Elementals and Conjurers suggests they are intrinsic spirits of nature. In my questing, I've only seen them manifest once and that was as allies during a Conjurer quest.

As for power, didn't the Elementals trigger the end of one of the Astral Eras due to the abuse of magic during the war of the Magi and the damage it was inflicting on the land?

Regardless, I'd say a fairer description would be one of landlord and tenant. Those living in Twelveswood are living in the home of the Elementals. Add to that that said Landlord has been burned badly by the behaviour of previous tenants. Its hardly surprising that the Elementals have little tolerance.