Why do people think that Pagan is a copy of Vaas?
Because they are both unique, that is why! People are used to villains that are boring and stereotypical, which is definitely NOT Vaas or Pagan Min.
They are very different:
PAGAN MIN:
-Outsider
-Self appointed king
-Truly friendly when the game starts
-Arrogant, corrupted by power, not insane
-Does not yell at people, but threatens them in a voice that a parent would use on their children
-Racist towards natives
-Acts civil
-Prefers not to get his hands dirty
-Wears his mothers's jacket as a tribute
-Looks completely out of place, has his own style
VAAS MONTENEGRO
-Native
-Works under command of Hoyt
-Not friendly
-Corrupted by drugs and power, insane
-Can easily threaten without yelling, but is at his scariest when he loses his temper
-Not racist, does place himself higher than everybody else
-Barbaric at certain stages
-Enjoys killing
-Rejected his ancestors
-Fits in between his pirates
And if you look at the two, there is much more difference between the two. Especially in the way they act.