Hairworks is 90% parameter driven, from having base guide comb (shape of main hairs that all fake hairs will inherit from) you can get VASTLY different results depending on parameter setup, which include (but are not limited to) stiffness, waviness, clumping, and such.
High stiffness will make hair behave much like polygonal hair, with very little deformation based on gravity or wind, it's also split in parameters like root stiffness, tip stiffness or overall and bending stifness.
You can really go to town with each parameter. Which is mainly the reason i guess why CDPR only really opted for making hairworks for Geralt.
Making HW for animals is easy, use low LOD mesh as growth mesh, mask out some areas where you don't want fur to grow from, adjust length (or just use attenuate function) and then give it minimal stiffness, waviness or clumping and it's pretty much done. But for humans it's incredibly tedious process, from making guides that would relatively resemble a human hair style to assigning params to make it look good without going overboard.
