I've always taken a simplistic view of suspension operation, even knowing that doing so is glossing over the subtleties.
The springs are what hold you up and provide the resistance to suspension travel in either direction (you are literally twisting a steel bar to compress your suspension). I view the damping, both compression and rebound, as just that: a dampening on the rate of wheel movement.
With that simplistic view one could say that if you are having issues with suspension bottoming on big dips, the problem should be addressed via the spring rather than with improved damping. Of course the pogoing suggests the damping isn't up to snuff, either, so the shocks do need attention.
If you are going to do a replacement, you may want to search out some stiffer (higher rate) springs, especially in the rear.