That's not an argument imo. The T-34/85 is way to cheap for his performance. And by the way the price differential between the Cromwell and the Comet is a lot higher.
Fact is:
T34/85 is CHEAPER although the unit has MORE HP than the P4J. Thats not justified.
Bring down the HP to the same level as the P4J and the price is justified. As long as it have more HP it needs to be more expensive.
You get ALOT more from the crom/comet difference so you should get more out of it... Like seriously use THAT as a metric the 85 is UP. comet gets more range, pen, armour, health, abilities and vet.... Compared to more health and more pen (despite what some people on the forum might cry about, 10 armour is negligible)
alternatively, the okw p4 gets the ability to bounce enemy shots for the same price of the 85. Guaranteed 1 extra shot or potentially many shots and no repairs required.
Its justified because for 40 fuel more than the tank its supposed to replace which is determined roughly balanced in the faction.
Don't compare it to the german versions. Compare it to the t34/76 because that's the direct comparison in every way including faction design.
Compared to a t34/76 the 85 isn't THAT much better Given that say 40% cost increase. It does have great pen but if yuu want to pay that much for armoured AT with that durability youll get the su85.
Using your example of before, you wouldn't even consider paying 155 fuel (cromwell x 1.4) for a cromwell that had a bit more pe, you will just get the firefly.
For a doctrinal "unit replacement" yuu need to look at relative "value" compared to the unit its supposed to replace, not the units its fighting.
Compare STOCK units against each other for relative cost efficiency the base doctrinal uniys against THEIR stock units.
(basically if faction A's "thing" is 10% more cost-effective armour and B is 10% LESS, (say 90 fuel and 110 fuel respectively, for the EXACT same tank) and that is part of their faction design then trying to balance a 100 fuel tank for EACH of them would result in different results, you would need to determine what 100 fuel can buy relative to the faction you are dealing with. Basicly for the first dude the new tank would need to be better than what they have and for faction B the 100 fuel tank would have to be worse than what they have stock. You can't balance doctrinal units against the stock units of another faction, not when it's a clear replacement anyways...
To replace the 76, in the same tier, but for an extra 40% cost the 85mm needs more than JUST extra pen. This can be accomplished by more ability and utilities OR more stats. It currently has the latter.