I think your underestimation is vast. According to census data in the US alone we're looking at 5,000 unique first names (at least). So even if we throw out t

I think your underestimation is vast. According to census data in the US alone we're looking at 5,000 unique first names (at least). So even if we throw out the fact that there are probably upwards of 100k unique last names... combining 5,000 first middle and last name variations puts us in the range of 125 billion unique combinations in English alone.