What can I expect from a Class 6 pattern of balding?

The way this should be approached, is to analyse your hair with respect to its hair thickness (fine, medium or coarse, the coarser being better than fine hair), and the donor density.  The number of grafts that can be safely moved in a Class 6 pattern of balding depends upon the donor density. The higher the donor density, the more grafts you have to move.  A typical Caucasian male has ~110,000 hairs on their head with 50,000 Follicular units, or 2.2 hairs per cm square. There is a difference between FUE and Strip surgery maximum numbers as you can see in this chart: https://newhair.com/resources/#tab-id-4 so your doctor should measure your original donor density so that a plan for both the first transplant and the potential to cover the entire balding area with an additional transplant can be determined.  A typical Caucasian with an average weight hair (thickness) can get reasonable coverage of a Class 6 balding pattern. Body hair is never as good, because the growth cycles are short and the length and thickness never matches the donor hair from the scalp in quality and length. If you don’t have enough hair, then Scalp Micropigmentation can make up the difference very nicely as shown in this article I wrote last year: https://newhair.com/wp-content/uploads/2018/11/Combining_Follicular_Unit_Extraction_and_Scalp.98621.pdf