well if you want to balance racials like that, then make wotf trigger 30 seconds on trinket and dont make you fear immune for 5 seonds.
its unfair that undead is pretty much a 1 win agaisnt warlocks
jokes aside.
perception only gets really strong when its a rogue itself. getting the opener on other rogues BUT wotf on rogues is such an insta advantage as soon as there is a priest/warlock/warrior fear.
SO basically up there is orc=dwarf>Undead>Gnome>B11(on melee classes)>Tauren>Human=Troll
But thats just overall cause of the meta. It really depends on what you face and what you play.