Twig mainhand yes - Twig offhand no - Barbed Scale Whip no.
The low-delay thing is great for mainhand because melee classes get a
a mainhand damage bonus based on level. The damage bonus is added to the weapon's damage statistic. At level 40, the Twig is effectively an 8/10 weapon if wielded in Primary; at level 52, a 12/10 weapon; and at level 58, a 14/10 weapon. That's godly. It's amazing for aggro. My monk friend pulls aggro off my warrior constantly with his Twig.
For the offhand, there is no damage bonus, so ratio is the only thing that matters. There are a lot better ratio weapons than 4/11 or 3/10 available for the offhand.
And all of this is not taking into account weapon procs, an important related factor. Search these forums for threads about warrior aggro or threat or weapons and you'll find years of discussion.