You don't get it. PUI doesn't make 50 card sets. Japan has in the past made smaller set, and it's not too uncommon to see it, but PUI, the people who print these cards will not be printing the english equivilant of this set in the same small set. There's a 0% of that. What I see happening is I see PUI taking some promos from japan we haven't gotten, maybe throwing in some half decks from other sets, or maybe combining 2 sets and giving us a nice 120-150 card set.
And I honestly believe there will be half decks for this set, we just haven't found news about them. How many sets in the past have had half decks. FRLG had them, TRR had them, I can't remember if Deoxys had them, EM had them, I can't remember if Delta Species had them, I know LM had 1 half deck (banette), maybe more. There's a good chance this set will have half decks too. Maybe japan will release them after this set comes out and we just haven't recieved any news about it yet.