The armed forces in Axis victory timelines tend to go whole hog on the crazy wunderwaffen. I don't blame them, seeing the house-sized tanks is part of the appeal of having the Nazis win WWII. However, if you think about how the militaries of an Axis victory timeline would really be set up, what you'd get is the opposite. Assuming a geopolitical situation akin to The Man in the High Castle - that is, a world divided between Germany and Japan, both of whom are in a cold war - I suspect you would see something very different from the Games Workshop-esque Nazi war machines you see in fiction.
Armor won't get heavier, in fact, it will get lighter and more generalized. I assume that even if the Germans win, their wartime approach to building bigger and better tanks that are specialized to deal with a particular threat is a logistical nightmare. I suspect they'd learn from the Allies that having one tank that can be modified to do many different tanks is better than engineering a tank/a