Most mods use the 3D models of NPCs (all that I saw on Nexus at least), then if you make an NPC, it´s most of work alread done.
I don´t know the details, but lizards, dragonborn prolly could be made reciclying the 3D models from Divinity.
Considering that dragonborn do not have tails I don't see why they would have a skeleton different from humans. It would basically just be a different texture.