Men go bald b/c of high levels of androgens (testosterone/male hormones) & the hair follicles on the head are less resistant & end up dying. Particularly the ones directly on top of the head. Therefore, no surprise why many balding men get the "horseshoe".

I think they should just shave it or buzz it. My personal pref were it me would be to do like Jason Statham (e.g. buzzed super close). It's certainly not a universal truth as there are many factors that go into sexual desire but it would help explain why on "average" there are more balding men who appear to have high sex drives (?). It would make some sense anyway. Ijs.