In the absence of organized government in Somalia, who would provide training? Oh, since they are all muslims, the training would be provided by their racist bigoted piggish imams. Their training is crappy everywhere else, so why would it not be crappy in Somalia.
And come to think of it, the fourth pirate would have been born about the time of Blackhawk Down. He was born in the time when Americans were killed trying to make sure his parents were fed.