Other than the canister shot the Stuart will be mostly harmless, as its regular main gun can not kill your infantry like an American M8, and it does not have heavy crush. The Stuart has a devastating canister shot ability, that is its primary strength. Your Panzerfausts will also be your defense against the Stuart Light Tank. It is better to safely kill it using 2 Panzerfausts than having it repair itself and escape to fight another day. To get a safe shot at it make sure it is within reach of at least 2 Volks and fire 1-2 Panzerfausts. Once you reached Tier2 you can fearlessly engage the carrier.
Cover is absolutely essential against the Bren Carrier with any of your units. If you engage a Bren Carrier then you need to either evade it in the field until you have access to the Panzerfaust or fight it from green cover only. Having 2 Volks together means you can fight any single Tommie in the field. This is because even the (free) British Scout section is stronger than a Volksgrenadier section.
You will need to cluster your Volksgrenadiers a bit, which means, that you will keep at least 2 of your Volks squads together. The early game build order includes the teching to Kriegsbarracks, because only then your Volksgrenadiers will have access to the Panzerfaust. The Volksgrenadiers are the backbone of your army until the 10th to 12th minute.
