Oddly robbers/thieves are almost always humans or halflings or half breeds. Bandits and roughr sorts are more likely orcs or similar. Warriors can be any race. Even elves have a warrior class usually. Just different skills and attributes. Elves are usually skilled rather than brute strength warriors - archers, thrown weapons, skilled hand to hand. Humans and dwarves are more brute strength warriors with swords, battle ax, mace, etc.
My favorite race for a robber is the Khajiit which is a cat form. Just be carful when you steal from houses. I was stealing baskets n coins inside this traders home, right infront of him I didn't think he was gonna do anything. Oh but he did he tried to kill me.