We do ASFs in 1.3 groups and dont have many loses of pinks, aside from stillborns. The mothers will seperate the larger young usually and they take turns nursing. You do have to be wary though to wean them off at the appropriate age. The offspring of the mother needs to be weaned out before she drops another litter. Having two litters in the same cage from a single mother is too much and messes up the balance of females to offspring.