Just thinking about the structure/contents of Hero Packs.
So I think a hero’s obligation card is included in their special 15 cards and the Hero card itself is an additional card.
I think all nemesis sets are 5 cards.
So a pack could be:
Hero card x1
Hero set x15
Nemesis set x5
Player cards x39 (playset of 13 cards)
Another wrinkle is that if unique/limit 1 cards are in a pack they will probably only include one copy. And of course, since all hero packs are playable decks, I’m sure FFG won’t be beholden to any specific structure.