PAKs are so slow and often innacurate (yay RNG) that people will just drive right past them. If you watch vonivans stream or andy they will buy 3 and just purposely drive up to it and decrew it. they might lose one or two but at that point it doesnt matter because it was the only threat to their rush
More importantly PAKs are defensive and you cant push without vehicle support outside of your immediate defensive area because a t70 can float along the perimeter and hit where the PAK isnt - mobility
Teller mines work great 95% of the time (I've seen a t70 survive occasionally) but smart players will avoid main roads when t70 rushing. Worse its hard to even get the munitions for mines in the first place in a game with heavy soviet pressure on your resources
Shrecks are kited by a t70 and pgrens will then die when they try to retreat. Also 120 munitions is way too expensive
T70s could use a small speed/mobility nerf (its a tank not a race car) but the meta that gets them out at 9 mins in as much at fault too, if not more so
===================
Munition costs are voluntary for soviets (abilities) and mandatory for ostheer (upgrades). Thats a flawed balance that contributes to soviets having an easier time managing munitions
Worse the cost of a 120mm precision strike, which will instantly kill a squad or support weapon is only 45 munitions... as much as a frag grenade. Difference is frag grenades you see coming, and they dont launch from halfway across the map. GG
Demo charges require no upgrades, not even the minesweeper one for 30muns, and at 90mun will kill any squad/squads in the game outright. they probably tear up vehicles but I dont see people using them against that. Good bye vet3 PGREN squad 25 mins into a close game because you tried to capture a VP. Ostheer naturally cant build them for some reason
Not meaning to sound too skeptical but I get the impression you've played a lot more Ostheer than Soviets (especially in terms of reasonably high level games) and consequently you've experienced horrible situations a lot more as Ostheer than as Soviets and you're always on the receiving end rather than the using end of these units. Hence, you probably don't see the 120mm studiously missing everything you barrage at for half a game, you probably don't experience the frustration of your conscripts being incapable of scaling against grens because of LMGs (your spare munitions won't help you), you won't find a north Langres start where you have no munitions and no manpower and no fuel and in spite of killing a scout car, an FHT and the first Ostwind yet there's still no way back onto the field on account of how many tools the Ostheer have for sitting on that cutoff, you won't get a T-70 only for it to be cleverly ambushed by shreks/a pak and a faust and thus find yourself pretty screwed, or go for the Von Ivan T1-T3 T-70 rush, be fiercely contested and then struggle like hell to deal with P-IVs on account of backteching being prohibitively expensive. Similarly, a game where Von or Andy have the fuel to have THREE T-70s by the time the first PAK is out is usually a game they've already won rather than a typical close early game. If they had a similar fuel advantage as Ostheer they would be sitting very pretty.
This is just going off streams but it seems like most of the players who are very strong with both factions think the game is a bit Ostheer favoured, I think it's very hard to make an authoritative argument about the balance needing fixing when you only experience the frustrations of one faction.
(For instance, Von Ivan, if he's not massively winning a game, does not usually have a load of munis as Soviets because of how much he oorahs, molotovs and uses AT nades. Likewise, T1->T4 with Guard Motor is usually an extremely muni-expensive strategy... and Ostheer were successfully countering it even before both the SU-85 and the Soviet snipers received serious [albeit, imo, justified] nerfs)
Edit: watching your game... I'm not really sure it's good evidence for your arguments. You have a roughly even early game, then your first P-IV (which was able to arrive reasonably ahead of the SU-85 despite even fuel control) gets stopped from capitalising by running into a mine, and you lose your second vehicle (the Ostwind) as soon as it comes out thanks to playing very aggressively with it and getting it AT naded when you're aware an SU-85 should be around. After the Ostwind loss you fairly quickly lost most of your grens.
Tsubaki doesn't generally have a load more munis than you and I think it's reasonably obvious from the replay that your play, whilst you started off pretty well, really dropped the ball in the mid-game against a very good Soviet player on a map that's pretty good for the T1 T4 strat. TL/DR: looks like you got outplayed rather than a key top-level balance concern but what do I know?