The fashion industry is completely crazy that way. It's not just banana republic. Years ago I worked on a ordering system for a fashion retailer and it was mind-blowing. Orders would be filled on a best-effort basis. You order 1k black M and 1k blue L and you receive 1.5k L white and 500 XXL red for example. So we'd have not only to store the order but also what was received. On top of that the designer might change vendors between orders and now you have different SKUs for what's supposed to be the same product.