Is male pattern baldness guaranteed to progress to NW7 if left untreated or could it stop at NW5A on its own?

I want to get a transplant, but I want all the follicles used to create a thick, low hairline. Instead of a transplant that just leaves me less bald I want to combine a transplanted NW1 hairline with a partial hairpiece for the crown. This way I'd effectively have a 100% full head of hair. Right now it looks like my balding will stop at NW5A, which should leave me plenty of donor follicles and make the partial hairpiece manageable. However, if it'll progress past that this probably won't work.