Well to be fair thats how it was in vcoh (glorious shrek blobs, not saying we should shrek blob in coh2 though). PLayers relied on t2 heavily. Once again though you still have the stug, which in many cases is still good against infantry as well. The advantage here is the early arty potential and early brummbar.
Stug III is a great tank especially for its price. People really under estimate it. There really seems to be so much reliance on the p4 though.
The reliance on T2 in vCoH was mainly because of the Grenadiers coming from T2, and Grenspam with Medic Bunker and Vet was really good. With support from AT guns (free AT gun stealth for Wehrmacht, anyone?) and maybe a halftrack (that could be upgraded to Flamethrowers or Walking Stuka as needed) you didn't NEED anything from higher tiers.
And I agree, the Stug is a pretty good vehicle in its own right, especially considering the price.
Right now, I'd say the problem with T4 isn't so much the teching costs- people would be getting it at least occasionally if the units in it were worth it.
But as it stands, the Panther is a one-trick pony, and not even that good at what it does. The same is true for the Brummbär.