I totally agree, However when the Panzerwerfer is compared to its direct counterpart (The kat truck) it is painfully obvious that the kat truck is simply just better at its job.
Kat truck can fire and hit units that hit T as soon as they hear the sound and catch units.
While the Panzerwerfer can fire on a immobile blob and kill 3 models. If it was a kat truck it would wipe most of those units.
Stuka is what panzerwefer wishes it can be when it grows up.
(Please note that I don't want the Panzerwefer to be better then Kat, those two units need to be equal is all)
Perhaps, they increase the accuracy modifier on the Panzerwerfer to scale with the Katyusha? I don't know how that would physically work, but I think it might increase the usage of the Panzerwerfer and upgrading to Battle Phase Three, in general.
Also, I agree with the fact that the Katyusha, even through all its previous nerfs/tweaks, still is a lot more potent then the Panzerwerfer. Perhaps, if we bring the Panzerwerfer back down to the Battle Phase Two building again, and allow the individual playing as the Wehrmacht to access it a bit earlier then the Soviet player, this could give an incentive to the Wehrmacht players to actually utilize it more frequently. I'm sure that there would be other issues that would arise with this, such as finding a replacement for the Panzerwerfer in the Battle Phase Three building, and also balancing the said artillery piece, so it isn't overwhelming and impossible to counter.