Mr. GQ:
some fishes might bite...
Actually IMO, a natural hairline needs temple closure, like Rahal, Armani, Cooley, Shapiro etc are offering. This strategy is a bit risky since hairs behind the temple point may be lost later, and the look may be very funny. Dannyskywalker, a Rahal's patient is now having some doubt or concern because the hair is starting to thin out behind the temple point.
Hairline from H&W or Feller is more conservative as it does not have temple closure, but does not look as nice or natural. Same for Armani's hairline, where the wall of hairs also look unnatural.