This is one of those great unanswered questions out there today. Personally I am convinced that this is all a conspiracy. You have to buy FIVE packs of buns and FOUR packs of hot dogs in order to use all the buns!!!
Actually, some brands do have eight packs. The main difference in why these come in different sets or packs is because the distributor may base packing on weight.
Well I believe that it is a conspiracy between the 2 companies so the consumer (us) has to end up buying 5 packs of buns for 4 packs of hot dogs. Hopefully you can eat that many before the buns go bad.