Can we stop ignoring the Puma's vet 1 ability? We are literally talking about the puma vs a turreted vehicle, and it has a turret lock ability. That can completely swing a fight against a Jackson and you left it out completely from this analysis
HVAP can certainly change puma to a 2-shot kill, but the longer aim-time could screw it hard against a Puma which has smoke to break contact and the ability to self-spot
Accuracy is the only point that I think is trouble. Could increase the target size of Jackson since most people already think it needs some nerfs against everything anyway. The armor nerf should happen regardless just to at least eliminate the rare p4 deflections
Even if the M36 never fired, you're still looking at a 60-80 second "chase" time (60 if the M36 has been hit once by a Pak40), which is going to be nigh-impossible considering the Puma's HP and armor.
We can shift around a bunch of other stats, but (IMO) we're still looking at a 33% shift in DPS between the two, which is really, really high regardless of how its done. Without causing massive knock-on problems, we can adjust any of the following (at least, from what I can tell):
Stat | Current value
Puma
Accuracy (far) = 0.025
Moving Mult = 0.5
Pen (far) = 80
Damage = 120
RoF = 4.33sec
M36
Target size = 24
Armor = 130 or 110 (OP's suggestion)
Note that changes to the Puma's Damage, RoF and even pen would have significant impacts on other areas of the game.
Why? Is it not possible Relic made a mistake?
It's possible, but I can't think of a time when an old change (2+ years) has been reverted because the core reasoning for the change was flawed. And as others have said, it would make Axis heavies (or panthers) extremely oppressive against USF.