Here is a copy of a ticket response I got from them today:
"Yes, we've read all of the feedback so far. The Panzerwerfer (rocket unit) has the same ability as Katyusha. She appears on the event map in the path you fight to earn her. Even though she is strong, she is vulnerable to commander artillery strikes.

The battles during this event are probably more on the difficult end of what was intended, and the next events we run will be much more manageable. We will probably make an adjustment in the final week to ease up tile 3 and 4. But that will be out on Oct. 25th, coinciding with a new character release."

I would prefer something sooner but they do seem to be acknowledging the problem.