Instancing Hair Strands 

Instancing is something that can pretty easily be done with parametric modifiers such as Curling or Frizz. You can Copy these modifiers and Paste Instanced to your other character.

If you want to instance the entire stack the second mesh needs to be exactly the same. For this you can instance both the hair and emitter object.

If you have another character that is similar but not exactly the same topology you can back out your guides by collapsing the stack. Then you can copy the Baked Guides and align it with your second character. Using the Ground Strands modifier you can associate these guides with the new mesh. Then you can add your instanced modifiers on top.