This is tricky territory. I personally do not like Jared Diamond's work very much, mostly because he's rehashing an argument that historians finished about 50 years ago. And his argument leaves little room for human agency and society. But, I think it's a loaded question to begin with. The idea that "white people" in general developed more cargo than "black people" is very simplistic and is really only taking into account a short time period. For most of history "white people" have not developed much cargo and if you wanted to rank civilizations they would not be at the top of that list. Furthermore, what is a "white person"? We know that perceptions of race are social constructs taht say more about the time period than any biological similarities and differences.

To get to the question though, look at the many African civilizations that were among the most powerful of their times. Egypt, Mali, Ethiopia; these were all powerful nations that exported a large amount of goods. Furthermore, we certainly can't forget China, which has arguably been the most powerful and progressive nation in the world until the 19th century. The reason that "white people" became involved in so much of the world trade that started with the age of exploration has much more to do with the social and economic factors in Europe than with any sort of large tallying of the amount of cargo they were transporting.

My final peeve with Jared Diamond is that history is not over. We have been living in a time period where "white people" seem to be on top, but that may pass at any point. Indeed, we may be witnessing the beginning of that transition right now. So, in a nutshell, I think the question is biased to begin with and doesn't accurately reflect historical reality.