You guys would be surprised at how often shoe companies change factory's. There are literally millions of shoe factories in Asia and companies are always looking to get the best product at the cheapest price, so factories will bid on their business, and the shoe company will pick the best fit. The problems come in when factories represent themselves at a certain level of competency, and then when it's time to produce those shoes, it's a whole different story. These shady factories will send the uppers to random stitching houses and then have them assembled with outsoles at another shifty factory, and the next thing you know, a whole years worth of footwear is fucked. The only places this doesn't really happen is with Nike/Adidas/Sporting Goods CompanyX, because they generally own or are financially invested in their factories.