There are hair models that should be created specifically for use. However, you could simulate a baldness/alopecia effect (in a simple way)... I mean, when a helmet is applied to any head, it takes a modular hairstyle "cut" parameter/cod as a reference. If a helmet is given a non-existent mesh the effect on a certain hairstyle looks like this:
All hairstyles have helmet applications using the "hair_cover_type" code
Perhaps this could be reinterpreted by someone who is proficient in the language of C# and get alopecic hairstyles through it.
Just imaging... quick ideas.