MMA Elite is clearly a take off of the Mixed Martial Arts frenzy. Having established that brand in apparel and equipment MMA Elite is going for something called "brand extension". Its almost like licensing except that it is all in-house. A salesman trying to sell an athletic line to a store can make best use of his time if he has a complete line of products to offer. Especially those that are like branded.
But 2,000 suppliers may have contracts with Walmart in just the apparel area alone. And in pushing their stock its not surprising that they would mention that they have contracts of some sort with Walmart. But that doesn't mean Walmart will kick out its already established supplement supplier in order to please one of their 2,000 apparel suppliers.