True, Roonans did appear in the Clone Wars project, however it's not a game. =) There was a senator too, the one who liked that pie with an unusual fruit. However he was not voiced as interestingly as those traders in Corusmall. Their lines, which are a few, had charisma, character and perhaps more.
Before the game I never actually noticed them, though by that time I had seen Episode I. The voicing was so good, that I had no doubt - these humanoids did exist in Star Wars universe.