While Amazon does clearly state under the heading you gave that they do track commingled inventory, they do not explain how. It is still possible that doing so

While Amazon does clearly state under the heading you gave that they do track commingled inventory, they do not explain how. It is still possible that doing so presents a 'massive problem' as the previous comment, apparently from an ex-Amazon employee states. On the face of it, I cannot see how it would present a problem, except for the obvious one of scale. It would be interesting to learn the precise details of how Amazon implements its tracking policy.