There's really no reason for heavies to be as powerful as they are. I'd suggest lowering the damage done by heavy guns to where it does a similar damage to other heaviest like medium to medium damage does (i.e. a little over half health) it's ridiculous that a heavy can one-shot a medium to the front plate.
#Nerf Heavy Tanks (or buff mediums)
spiral scarab
zinc kiln
A good nerf would be to increase the resource cost to pull one, increase the cooldown, and put a hard cap on how many heavies can get pulled per game. Also nerf panther as a whole
finite slate
There's really no reason for heavies to be as powerful as they are. I'd sugge...
This would make no sense for some tanks such as the Tiger or the Is-1 so i understand your point but a better way this could work is code a way to do damage based of distance and location of impact which has been explained by people in other suggestions smarter than I am so I'd recommend looking around for the other suggestions but other than that 
warm crescent
A good nerf would be to increase the resource cost to pull one, increase the coo...
A good nerf would be to reduce the damg. And increase it of the tiger.
jaunty wraith
elder flicker
inland wagon
I don't know, majority of the Yank tanks are pretty useless compared to the P4 and Panther. We were in a P4 the other day and survived 6 rockets, most of them to the front. If that were a Yank medium we would have died after 3 rockets 😂
indigo garden
Yeah because the Bazooka is horrible for some reason and it can’t pen the Luchs or Panzer IV frontally while the PIAT and Panzerschreck can pen everything up to a Medium Frontally and heavies in the side