In Uncharted 1 you had pirates who had scars, tattoos, different faces, eye patches, etc. Take Prakoso and Mac for example.
Then in Uncharted 3 there is only 3 pirates with different faces and that is white, black and asian. They don't have any scars, tattoos, different faces or anything to look like real pirates. Oh and that white guy's face is also the same face for one of Marlowe's agent 44 skin (talk about lazy).
The random pedestrians, the guys at the bar and most of Marlowe's men have more different faces than those three pirates.
By comparison, the Uncharted series actually removed itself from the modern day pirate enemy after the first game was done for the most part. In the first game Drake handed that famous quote to Elena about there being pirates in search of the treasure as he was. Later on Drake was battling armored mercenary and thug types. The shipyard level of the game is where he scuffles with me hardies, but not forever.