the cost of the 85 cant be compared vs other factions medium tanks because the soviet medium armour doesnt follow the rules that the other factions do.
This, ffs.
All you people trying to argue over which medium is the most cost-efficient need to stop getting bogged down in stats and hypothetical 1v1s. Trying to distill all the aspects of a unit's stats, vet abilities, timings, synergy with other units etc. into some quantifiable measure of 'performance' is totally impossible. It can be a useful place to start but it's not enough to make any serious decisions with.
Also, the idea that all similar units should be equal in cost-effectiveness is not only impossible but it's also completely unnecessary. IMO it's fine that one faction has a better-value medium tank than another, because some factions rely heavily on meds for their late game while others lean more on heavy tanks or TDs. Of course, this can become a problem when the efficiency gap is too large, or if a faction has the advantage across-the-board, but that doesn't apply to the current situation.
T34/85 is fine. It still has all the same drawbacks - lackluster accuracy, crappy abilities, high micro requirement. The only thing that changed was the MG and it really wasn't by much.