It really depends on what the Soviet is doing. If they do a constant stream of flamers in HT's mixed in with a few Conscripts then a fast AC would work fine.
It's quite simple to determine whether or not the German player is doing some kind of T2 rush. If they're completely giving up map control and you've only seen 1 or 2 pioneers, the most logical option would be to upgrade AT grenades and get maybe a single scout car instead of two, then tech to t3 or t4. Scout cars counter PGs pretty hard, unlike Grenadiers, and there is nothing stopping the Soviet player from rushing the scout car into the German's base once the conscripts double AT grenaded the German AC. Even if the German player doesn't rush an AC with their T2, scout cars counter PGs (no panzerfaust, a single panzershrekt doesn't do enough damage to disable the car before the PGs have to retreat). In the time it takes for the German player to get out enough forces to reasonably counter the Soviets, they'll have teched to T34s or SU-76s, both of which counter PGs, ACs, and the SU-76 counters AT guns, not to mention Conscripts and Engineers with flamethrowers will counter AT guns by themselves.
Especially in 1v1, fuel is an important resource, and when one player has both fuels or most of the map, their first tank will come out earlier than the other player will be able to deal with it appropriately. Giving up early map control means giving up a massive fuel income