Lore is important here. Neither the Kul Tiran Thornspeakers, or the Zandalari Dinomancers are Druids. They get their power from the Drust, and Loa respectively.
The only Druids that Azeroth has are the Night Elves, Tauren (Both Mulgore, and Highmountain) Darkspear Trolls, and Gilnean Humans.
The forms are based off of the Wild Gods. These Ancients grant us their blessing and allow us to take on their form as their aspect. Currently we embody Ursoc, Ashmane, Malorne, Aviana and Ela’lothen. The aspect of Goldrinn (The wolf) is called pack form and is forbidden as it’s too aggressive.
You could make an argument for Tortolla and Agamaggan, but Blizz seem pretty firm on the ones we currently use.
You shouldn’t break the lore just for gameplay cosmetics.
The only reason the Kul Tiran’s and Zandalari are in the Druid branch is because Blizz didn’t want to make two completely new classes just for two sub-races. (Which is understandable.) They are not; however; Druids. They have no connection to the Emerald Dream or the Wild Gods.