That's right
As you increase the amount of resistance (more shocks) you will make the suspension stiffer. More shocks help with more load. Think about the Rancho RS9000's. When you run empty, you are supposed to adjust them to the lightest setting to get a softer ride. The stiffer shock (or more shocks) is to keep the load from bouncing when you have a lot of weight. Most of the harshness of the ride comes from the fact that you have very heavy springs to take a large load. When you drive empty, there is not enough force to make the springs compress and it just moves the whole truck instead. I hope this helps.