I'm in the planning stage for a future campaign and was looking over the options for archetypes with some of my players when the question of additional Transfored Animals came up and I was wondering what the ideal modifications might be needed or if I'm missing something about additional archetypes?
Chapter 10, "Former Animals Anonymous" should be able to help you with that. In particular p178, "Mini-archetypes."
What he said. That page 178 is super helpful for exactly this.