How about pricing units according to their performance? This thread is not about making it the best medium tank, its just about increasing its pen so it won't bounce shots against units that are cheaper hence having a chance to win against unit that have the same role, but destroy the p4 in a 1vs1.
In my opinion a lot of it starts with the kubelwagen in the 3v3 and 4v4 mode, since the maps are realy wide. Therefor a kubel can cap territories really quickly and the player can just move his troops to the frontline. Therefore it's really hard to get some feet onto the ground. Also you have a lack of resource income. The fact that you meet a light tank at the moment you could have a light tank too if you had normal resource income is negated by the kubelwagen.