Some are virtually entirely based on trade: Singapore. Hong Kong (as an autonomous region of China), etc.
But the comparison was more one of size and scale of operations.
WalMart has an annual income of $482 billion.[1]
That's more than the annual GDP of Poland, as measured by the World Bank, the 25th largest economy in the world, and of Belgium, the Philippines, Thailand, Norway, Iran, Austria, the United Arab Emirates, Egypt, South Africa, Hong Kong, Malaysia, ... and 153 other countries (163 total) in the world.[2]
It carries nearly a third of a million distinct products -- 291,000 unique SKUs across all channels, some 100k per store.
It employs 2.2 million people.[4] That's more than Macedonia (#143), but might better be considered as
It has 11,620 stores worldwide. Each is comparable to the business district of a small town, and in many cases is.[5] Wikipedia only lists cities in the US of 100,000 or more population in the United States, there are 304 such.[6] There are a total of 35,000 recognised place names of cities or towns in the US, most quite small.[7]
Of course, that's being a tad unfair to WalMart, perhaps, and the company has all the advantages of modern computers and such which earlier command economies did not have. Clearly, it would be impossible for an early 20th century or earlier command economy to have claimed a significant share of any national economy, let alone the global economy.
Except of course, for the fact that the East India Company which effectively was the corporate state of India, and comprised half the world's trade at the 18th and early 19th centuries.[8] A prime example some Prussian-born economic critic living in England in the 1840s might well have been aware of.
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Notes:
1. Annual Financials for Wal-Mart Stores Inc. https://secure.marketwatch.com/investing/stock/WMT/financial...
2. https://en.wikipedia.org/wiki/List_of_countries_by_GDP_%28no... WalMart itself claims it would rank 19th, see note 5.
3. https://www.quora.com/How-many-SKUs-does-Walmart-carry
4. http://www.usatoday.com/story/money/business/2013/08/22/ten-...
5. http://www.statisticbrain.com/wal-mart-company-statistics/
6. https://en.wikipedia.org/wiki/List_of_American_cities_by_pop...
7. https://www.reference.com/geography/many-cities-united-state...