3) The next problem is not the first T34 vs PIV. The thing is, that you can get over the whole game faster, easier and more t34 than pivs, because of less manpower cost (55) and less fuel cost (30 fuel) and 2 less popcap for each tank.
Other factions don't really need to pump out more mediums in the first place. It's not the cheapest tank that is most cost efficient. It's the one that survives and gets vet. The reason why OKW PIV or T34/85 are so much better than other mediums is because they can easily stay alive with decent enough micro due to their superb armour and/or HP pool, and this is also why heavies so popular on previous patch. Thanks to that you can save massive amount of resources just by not losing tanks while also gaining vet. While stock OST PIV without vet 2 isn't so tanky as other mediums, it still has mutiple vet abilities that heavily improve its survivability and specifically in the SOV matchup it doesn't have to fear anything other than SU 85 and ZIS. Baby AT guns, T34 and Cons can only force it to retreat, not kill it.
T34 meanwhile does the exact opposite in later stages of the game, it tends to bleed resources. At the same time it has pretty low performance per pop. For 10 pop you get decent AI, no armour to speak of and highly unreliable AT. Other mediums except for Cromwell all bring better AI, AT to tackle mediums and armour that usually warrants at least one bounce in a direct engagement, so double the power/utility for only 20–40 % more pop. In that light T34/76 doesn't appear so efficient, does it?
In the light of this discussion, I think comapring T34/76 with PIV is not even the correct thing to do. It should be comapred to Ostwind instead, as the price is similar, AI performance is slightly worse and both of them can only damage opponent's medium through rear armour and both of them suck in long high pop games. While T34 is technically better at AT, Ostwind typically goes up against low-armour targets like the T34, whereas T34 faces mediums with high armour like the PIV or Panther. But Ostwind hits the field at even better timing than the PIV...