Interesting post, I checked the current OWGR and did some calculations of top 100 players from various Countries, per population. Looks like the UK and Ireland do just fine...
Country # Players Per Population (Approx)
North Ireland 2 900,000
Scotland 2 2,750,000
England 14 4,000,000
Ireland 1 4,500,000
Australia 5 5,000,000
USA 42 7,800,000
South Korea 4 12,750,000
South Africa 4 14,250,000
Spain 3 15,600,000
China and India with a combined 1/3 of the worlds population.... 0!