Yes, the PzGrens with shrecks are so OP.
Also I believe cons with their mossins are so OP. They should be equiped with slings.
I see comparing the best infantry AT combined with one of the best infantry AI really compares to the weakest infantry. They weren't as bad when STs were gods. But now they lost a small amount of armor and nearly doubled their AI this patch. Means a shrekd Pgren can flank and kill a zis almost as well as AI Pgrens prepatch.
Now having shrekd as primary AT and backing them up with an Ostwind or a Brummbar is even more viable since they can whipe a zis a lot easier.