A lot of small co-op groceries and even food co-ops that are more like ordering clubs used to use a company called UNFI to put in their orders but I think they focused more on organic and other high end items but they were willing to service smaller stores so yeah it's probable. There was also IGA (independent grocers association) but I think most of the stores associated with that brand/network locally have closed down so not sure if it's a thing anymore. Many of the independent convenience stores here stock almost all of their groceries at Aldi.