The Alliance is full of redundant races.
The Gnomes are the masters of engineering, but the Dwarves can be too, though Blizzard usually defaults to using a Human NPC.
The Draenei were originally often scripted/set-up as the rivals to the Orcs… but so were the Night Elves and Humans in promotional material.
The Alliance ARs are just their base race but them to a greater degree.