Next revisions were made. Partway into the design of L2, which is the other major alternate for this model (that doesn't require matrix animation) I realized it was going to be way too flat, so I scrapped it. Matrix animation is a must.
Next, I put the L1 design through two more iterations, taking away as much as I could see to take away, and I think I have a good solution with L1B. It has 6 layout types, and 13 shape types. Seems to provide a good tradeoff between coverage and complexity, animals should still have fairly interesting faces, necks, tails, bodies, arms/legs, and backs, but it's less complex overall.
So! I must implement matrix animation, which shouldn't be so hard (really I'm almost more worried about the blender export module than anything) and then I can start to implement this thing!