Hi David, welcome to DA. Your work has a lot of skill and style. It's hard to imagine what issues you have with the chavant by the looks of your horse, it looks great!
I use a variety of materials including chavant, it depends on what I'm creating and how big it is. Many times I will use a resin casting of something I've created in the past and modify it using a material called Apoxie Sculpt. It's available from Aves Studio in Wisconsin. They have a website. Let me know what issues you have with the clay and maybe I can offer a solution.