I have 4c natural hair and the back of my head is drier and shorter than the rest of my head.
Yup, welcome to being natural! As for the dryness, I recommend Le Kair Cholesterol treatment as a conditioner. Condition for an hour with it after washing your hair. Then, the next wash day just use as a DC for 30 minutes. That fixed my moisture retention problems. Maybe it will help you out.I'm also shorter at the back. Hair growth can be uneven in some people, it's just the way of nature.