I have made various formulations using Lard and Tallow but me personally I couldn't see any real advantage over a single tallow soap. I think from memory it was marginally creamier but didn't retain that body for as long as Tallow only. It didn't smell like bacon
I can see a Pig meets vegan soap in my near future. Stearic, Lard, Coconut, Avocado, Macadamia and Kokum or Shea butter to super fat.
Stearic acid is the main ingredient requirement for the majority of soap features. Tallow, Lard, Shea butter, Kokum Butter and a couple of others provide a good percentage of Stearic but straight Stearic Acid as a refined soap making ingredient is usually the bulk of all traditional saponified shaving soaps. It is easy to make a shaving soap for yourself but to make a soap that satisfies a commercial market is a whole 'nother level.