Swapping the P4 and the Panzerwerfer would be the only feasible option honestly. But even then, the implications are pretty significant. Ostheer T4 would be in such a sorry state. Everyone would just use call-in tigers or command tanks instead of bothering with T4.
Any time I look at Ostheer's tiers and teching I just can't help but feel that CoH1 Wehrmacht unit composition was superior in every way, design-wise.
Panzerwerfer being an upgrade for halftracks @ t4 was an excellent notion, and the nebelwerfer in T3 filled its role spectacularly.
Between Ostheer and OKW there's the tools for two well designed factions, they've just been mixed up between each other.
(Hell I made a mod that essentially merged the two and it actually worked pretty well. You just have to break from the current system of design to make the factions work. It really takes more than a few unit swaps. Redesign is more appropriate than rebalance.)
