Nike Inc. heightened its legitimate fight with sneaker commercial center StockX, saying it acquired four sets of fake shoes on the stage in spite of the company’s guarantees that it is as it was showcasing authentic footwear. The world’s biggest athletic-wear producer inquired a federal judge to let it include claims of counterfeiting and untrue promotion to the current trademark-infringement claim against StockX. It said it got the fake shoes, counting a fake Jordan 1 Retro High OG, from the marketplace between December and January. “Those four sets of fake shoes were all acquired inside a brief two-month period on StockX’s stage, all…