Interesting. Do you have scatter values? I've tried the Pershing a few times and at vet 0 it seems like it has much worse scatter than a HE Sherman. It seemed kind of underwhelming at vet 0 but decent at Vet 2 or better.
Both tanks have an angular scatter of 6, but the Pershing pulls ahead due to having a lower distance scatter (4.2 vs 5.5). Hence the size of the HE-Sherman's scatter cone is roughly 25% larger than that of the Pershing.
AOE Profile (upper panel) and size of scatter area (lower panel) as a function of distance