You may need shocks, though I would guess it's maybe a 50/50 chance. Shocks generally, though, do not improve ride except on very bumpy roads, e.g. potholes and RR tracks. They are there to prevent chassis bouncing, basically to keep the wheels in contact with the road when the springs re-bound after a hole or bump. If your coach bounces several times after a bump, you need shocks. If it dips & rises once, you do not.
Ride smoothness is largely a matter of tire pressure and the springs. Excessive tire pressure results in a very firm ride, so get the coach weighed and adjust pressures per the tire makers load/inflation table. Heavily loaded springs don't have much reserve and act stiff and can "bottom out". Not much to do about that except to re-distribute or reduce load, and that may not be practical in all cases. Or add some "helper" springs (usually air) to assist.
Kelderman is an expert in motorhome ride improvements, but the products aren't cheap.