The AI in Sea Dogs is a delicate instrument. It considers the firepower of enemies, different brands of cannon shot, the captain's abilities, wind direction and more. When a person can have up to three allies, the AI becomes quite complicated. Plus, enemies can have also three allies. If it's one merchant protected with two war vessels, the two warships will cut off from the merchant and submerge the gamer as soon as possible, while the merchant will run off.
Pirates board an opponent as soon as possible to get the gold and other goods.
You can read the rest here. Get your copy here. Each enemy has unique behaviour patterns, yes. This is mostly due to the inherent special abilities present in each enemy race. You can read the rest of the interview here.