Could Provoke be a little bit Fell Cleave proof?

[Freyyy]

Or they could just make it work like taunts work in most other MMOs, where it basically forces the enemy's target on you for like 5-6 seconds regardless of who has aggro, on top of giving you the top threat +1. Making it like this would prevent this kind of issue and 5-6 seconds is enough to secure hate on you. This could also be used in PvP to force an enemy to target you and make him unable to switch targets for the duration of it. Some games have this too.

Edit: I'll just add that I find it unnecessary anyway since you should prepare your tank swap by preparing a 3rd stage threat combo beforehand (like doing Hard Slash - Spinning Slash before voking, and Power Slash right after voke, which you can ani-cancel with an oGCD to get the damage and threat ASAP), which is enough to keep aggro, even to a Zerk'd crit Fell Cleave.