Taking a look at my stats in terms of wins/losses, you can see that I have a 51.3% winning percentage in my main tank, the StuG, which matches close to what I got in the Hetzer and Marder. My light tank shennanigans have got my up to 56.4% in that tank, but my Panzer IV frustrations keep me low at 36.3%. Ouch. Considering there is a lot of external factors to consider (random teams on random maps) you can figure that my percentage in the Pz IV are indicative of not helping my team very much so far. Hopefully a bigger gun will help.