You’d think that with double-digit industry sales growth in the first half of this year, China’s richest retailers would have an easy time increasing their wealth from a year earlier on the new Forbes China Rich List. Yet retailers were a mixed group. That was in part because the industry’s brisk growth is attracting increasing stiff competition, from electronics suppliers to supermarkets. It’s also because some of the older players haven’t been fast enough to address changes in taste, and in a competitive landscape like China’s, it’s easy to fall behind in a hurry.