Rogerson every head of hair is different and it depends on your personal hair characteristics. Some guys can get away with single hairs from the occipital zone in the hairline. For instance and this is just generally speaking guys from Italy, Mexico, India seem to have darker thicker caliber hairs even in the hairline so it s not as much of an issue. Those with finer, lighter hairs in the hairline are simply not going to look natural with thicker darker hairs from their occipital zone in their hair line so they need to have hairs harvested outside of that zone on the periphery which can only be accomplished with FUE.
Here is an experiment I believe should be mandatory of all prospective HT patients. Take some honey or maple syrup and apply it to the hair line zone. Now cut some hairs from the occipital zone and stick them to that same area. How well does it blend in with the surrounding hair?
There is no standard answer to your question regarding how many grafts are needed to lower a hairline. How big is your head? What type of caliber hairs do you have? What is the surrounding density? ¦ ¦.etc ¦ ¦ ¦too many unknowns ¦ ¦ ¦ ¦ ¦ ¦go in for some consultations in person or online ¦ ¦ ¦ ¦ ¦..then start cross references opinions ¦ ¦ ¦ ¦ ¦ ¦ ¦ ¦ ¦