Gonna go on a limb and say this would be a great opportunity to throw in Class Skins, and have Gnome and Goblin 'Tinkers' with Mech Forms and lasers and rockets to replace the beast forms and nature magic.
I'm not sold on the concept of Gnomes going Hamster mode, even if it's a funny idea. I think the gameplay could easily be adapted with different forms, and we could give Gnomes and Goblins something that really works with their race rather than trying to lump em in with the rest of the Druids. I mean, they'd have to spend time making unique size-appropriate Beast forms for them anyways, might as well put that effort into designing something that fits their aesthetic instead, and just repurpose the Druid gameplay with some spanky new FX.