Consider that 100 range is enough to park a PaK behind the tree line in crossing in the woods and all but hit the enemy base, too. 100 range may seem great for 4v4, but maps are a lot smaller for 1v1 and 2v2.
We have seen too many matches with 100 range Elephants and ISU-152s. Moreover; they are mobile units.. Pak deserves that kind of range due to its immobility..