715, I think things are better balanced now.
Based on results of more online testing completed today, we modified the mix of Tigers and Shermans. The allies now have 10 Shermans out of 34 tanks total, and the axis now has 8 Tigers out of 29 tanks total (as opposed to the previous 50/50 mix).
In testing, we took tanks out to various ranges and counted how many hits from a frontal attack it took to take out a turret and how many to kill the tank, with several people participating to average over skill at targetting. Tigers and Shermans are about equal (i.e., it takes about as many hits from a Tiger to a Sherman to knock out the Sherman as it takes from a Sherman to a Tiger to knock out the Tiger). Likewise, Panzers and T-34/76's seem actually the same. We tested at ranges from 2k out to 2.8k with both AP and HVAP rounds (AP seemed much better at range). However, as you say, while a Panzer can manage to kill a Sherman (although it is not as good a tank as the Sherman), the T-34/76 can't really knock out the Tiger from the front except at close ranges, shots into the tracks, or non-frontal shots. This new modification to the mix was judged to be decent by various folks involved in the testing, several of them being very-active tankers.