I would like to make a few suggestions for adjusting tank stats- namely the Tiger 1, IS-2 and Panther.
First, I think the Tiger 1 reliability should be increased as, after initial teething problems, its reliability was reported to be on par with the Panzer IV. In the mod, the reliability of the Tiger 1 is lower than that of the Tiger II, which does not make sense. I would suggest either swapping the reliability stats of the two tanks or increasing Tiger 1 reliability to 70%.

Secondly, also for the Tiger 1, the max speed should be adjusted. In real life, it had a top speed above that of the Panzer IV, (comparing the Tiger E variant to the Panzer G variant). Even if you do not want to compare these specific variants, the gap between the max speed of the two tanks in this mod is not warranted. I would suggest increasing the max speed of the Tiger 1 to 6km/h, at least.

Thirdly, I suggest decreasing the hard and soft attack of the IS-2 to mimic its low reload rate.

Subsequently, I suggest making the production cost of the Tiger 1 higher than that of the IS-2- raising that of the Tiger 1 and lowering that of the IS-2.

The Panther D variant should have a piercing value of 92, like the G variant as they had the same cannon.

These are just my suggestions from looking at the stats of a few of the tanks, I hope you find the suggestions useful and I would also like to compliment your development of this mod, the depth and mechanics are impressive and really improve the game.