Allow me to explain: oops.
I gathered information from several different sources, one of which was Wikipedia. The reports of how many troops each country sent varied widely. Wikipedia listed low numbers (although I admittedly used their figures for America and South Korea). They reported only 14,200 British troops were deployed.
But when I looked so more around I found that most places were giving higher figures. (Some implausibly high - I found one site that claimed 5.7 million Americans served in the Korean War.) I finally found one site that seemed credible - they not only listed troop level totals but also listed specific units, naval and air forces, and casualty counts. They seemed informed so I decided to go with their figures.
The problem was that I had already written the part about the ROC troops and said they were greater in number than the British (based on the 14,200 figure). I forgot to amend this when I revised the figures.
I blame Ed Zotti.