Torque arm question

[ITLBTU]

I was wondering how some of the aftermarket torque arms improve traction, and anti hop over the factory units? Some are just beefier looking units with an adjustment for the pinion angle. They look like they are the same length. I can see haw the GW TA would be an improvement over the factory. If I understand how they work, the shorter the TA the more "lifting" force can be applied to the chassis from the rear end. Maybe I need a better understanding of how a TA works.