Goblin Queen (She/Her/Hers)
That would be a good idea if the goal was to always keep the original deck and the “deck of many more things” competely separate. But since the intent is explicitly for DMs to be able to pick and choose cards from both to make their own custom deck(s) to suit their campaigns, having them be different sizes would be awful.It would actually be kind of interesting if the card size difference was real rather than a defect: one size for the original DoMT and the other for the new cards. Since there's no game where the size would matter, having two slightly different sizes would make it quick and easy to separate the two decks.
But I suppose that's unlikely, given this sort of defect is apparently common with other cards.