I've found that building T2>T3 works well. Get out a quick T70 to put axis on the back foot early. If you can keep your T70 alive and ranked up to vet2, then you can use it for spotting for your KV2. It has a huge range when locked down (comparable to the OKW Flak Base). Open maps work best for this strategy
You can see after the game is finished whether your bulletins stack or not. Flip your playercard tile, if there's just 1 bulletin then it means it didn't stack, if you have 3 then they did (assuming you equipped 3 of the same).