Right I think I'm ready to define my model scales. After a little bit of experimenting I can put some values down.
Standard Human Scale:
Pepakura Scale Factor: 3400
This is my attempt to keep all my human shaped models to scale to make them look better and more accurate as a group. For example no young and adult Malon who are the same size! Though it says humans/humanoids it could be used for some enemies or a general universal scale for everything. The result is most people will be 15-24cm tall.
Edit: In the past I've rigidly stuck to 3400 and with good results, but as I continue getting content, I've noticed that some characters will just be too big (Poes) and some too small (Saria is tiny when compared to the Adult cast!). So y'know there might be some lee-way with certain models, and some minor resizing for aesthetic or practical purposes.