[quote=IncredibleBee]
In the battle of Sekigahara, both the Western and Eastern armies mustered over 80,000 men. In a larger country, and especially a coalition, reaching several thousand would be no problem.
[/quote]

That was in 1600, much later middle ages time (end of the Tudors, which saw colonisation in America and mass gunpowder deployment before the battle.)
Only 80 years after that battle Blackbeard would be alive. This battle is long after the era we are in, and population is far more than proper medieval times. But I will agree, though difficult to field it would be possible to have an army of 80,000