Obviously chasing feared enemies is not popular, so instead of an entire rework how about instead make a change to the Skull of Resonance helmet to fix the problem. (it is already the shout helmet). Could make it work similarly to the WD helm.
Skull of Resonance
(change it from) - Threatening Shout has a chance to Charm enemies and cause them to join your side. (Barbarian Only)
(change to) - Threatening Shout gains the Terrify rune and feared enemies cower in place for 3-5 seconds.
Seems like a win win for everyone!