To expand on my idea... maybe make Assassin grant a 10% total enmity transfer to TA, then have the merits be an extra 3%/per instead... and collaborator should be reduced to a 30 second timer. Would make enmity control a much more active and viable job for THF.
Also would be cool to give THF a couple 'stances'... like-
Shadow- -15% DT when you're not the target of the mob, transfers 25% of your melee enmity to any target between you and your target, Boosts TAs enmity transfer
Antagonist- +15 enmity, crit rate bonus, critical att bonus on SA
Just ideas! Highly doubt we'll see anything like that from SE, would be quite a bit of work... besides, having TH is so super OP THF doesnt need anything else! (sarcasm)