All of your puppies sound normal to me. The puppy coat is growing out and the hair is getting longer....therefore the scalp is more noticeable with the light hair plus it is long enough on top now to start laying down a little more. If you run your finger across the top of their head you will probably feel a little "nubby" feeling. That is new hair growth. IF the hair is actually falling out, then there is a problem. However, it probably isn't. Hope this helped
