how to make flee

[LinK]

Fighting a war chief and before I can fight him I have to make a number of regular mobs flee. How does one do that? I've only ever seen captains and other boss stature mobs do that.

[Max]

Press Y (controller) to stealth kill an orc
Kill a captain
Kill a warchief

[SpawnCap]

Do brutalize attack on regular uruk, Y on controller while in stealth, and have epic rune that increases fear when doing brutalize attack, any uruk that isn't a chief or warchief in the area that sees you do the attack will run away, it will clear out pretty much everyone. I've been doing this since I started playing the game, it kinda feels like cheating it's so easy.