If your tires are wearing more on the outside than the inside, you're roll center is very low. Raising the roll center either by lowering the inside link or shortening the link will cause that wear to move inwards. I tune my roll centers based on tire wear.

A sway bar is a device that does increase roll stiffness but it never adds traction. It only takes it away. If my tire wear is where I want it but my steering isn't, I'll use a sway bar to even it out by adding a sway bar at the end that doesn't have a problem. In other words if the car is oversteering I'll add a bar in back.