If this were the case, why, you would be able to make a creature with body parts made of other creatures!
We could have real chimeras!
A -Dragon Head dragon head- on your *Lion Torso Lion Torso*?
Uh, no.
See, while having real chimeras is great (the severed heads would not say "chimera head/chimera head/chimera head", but "goat head/lion head/dragon head"), I was more reffering to thus;
The fabled MEGADWARF, whose body part materials would be made of the Dwarf material!
Dwarf skin (not skin of dwarfs, but skin made OF dwarfs), Dwarf muscle, and Dwarf bone.
I was hoping to have entire body parts that ARE dwarfs (as opposed to body parts that are comprised of various layers of dwarf), but the way the system works as I understand it, you can't specify a material for "arm", but rather, "arm skin", "arm muscle", and "arm bone".
This is all assuming that creatures and body parts created or shipped in the Raws retroactively have a material designated after them, which I severely hope is the case.