How should streetwear brands plan size ratios before reordering pants or sweatpants?

Streetwear brands should not reorder pants or sweatpants with the same size ratio automatically. A smarter reorder should be based on actual sell-through data. If sizes M, L, and XL sold faster than XS or XXL, the reorder ratio should change. If one color sold slowly, it should not receive the same quantity again. Brands should also review return reasons, customer feedback, fit comments, wholesale demand, and seasonality. For example, heavyweight fleece sweatpants may perform better before fall and winter, while lightweight nylon or track pants may perform better in warmer seasons. Reorder planning should protect both inventory efficiency and customer demand.