Every single harem in a dedicated harem series is but an act of god, an event where a single man or woman and a handful of others from preferred sexes succumb to the universe's whims
So many opportunities to look nice and/or heroic, so many coincidences that bring these characters together, so many other accidents that cause any break in the balance to suddenly be prevented or leveled again.
Being a harem protagonist is like being a fighting shounen protagonist. One must gain the right amount of luck, show just the right amount of finesse and charm, the other must show iron will, friendship and a body and mind suitable for gaining power. There is no other option.
There is no personal talent, no will, no choice, only genre.
It'd honestly be fitting to say "Welcome to your hidden Tartarus!"