I think Panzer 2 is a must, it is unique and i haven seen before.
I dont think another KT is needed ingame.Its just a huge fortress of steel.i would probably prefer Tiger I's instead, for the reason mobilityand originality of the Wehrmacht.
In German service the panzer 38(t) was used as a substitute for the Panzer III.
Here are my choices and the reasoning behind them, Panzer3, Good support tank, fast, cheapish, not so good vs. other tanks, maybe a upgrade with side armor, Panther, it’s the Eastern Front deal with it, Jk perhaps a upgrade with side armor and top MG,Ferdinand, why? Each axis army has their own super heavy tank, Wher has King Tiger, PE has the Jagdpanther, the Ostheer should have their own, and like the armies it would be one time call-in, k? Marder 2, maybe a little cheaper than the 3rd version, like wise weaker in terms of damage, health and sight radius, StuG 3, widely used, good main gun & front armor, upgrades with side armor and Mg, perhaps an armor piecing ability like American AT gun,Jagdpanzer, Unique unit, better than the StuG 3 in terms of both damage and armor, perhaps a call-in unit like the Hetzer, Wespe, Think Hummel but smaller and weaker, in terms of damage, armor, and range, in would be a call-in unit, like the Katyusha,10.5cm Howitzer, this unit would be literally an exact copy of the American 105 Howitzer, 3 men, very vulnerable, easy to capture, has great range and accuracy, now to make it different than its American counterpart, it could have better accuracy than the 105 but not fire as many shells,
in all honesty the KT in the game now is 79 tons of rolling fail