>>538794808
>Choosing "Join Any Faction" gives more exp but then you can't focus down Soviets.
Also depends if you want to progress a more natural balanced way through the BRs or just beeline straight towards the IS-2 (1944). It'll be tricky if you beeline strat because you'll have the IS-2 for one squad but have much lower BR gear for your other squads. Just get some BR2 or BR3 smgs since they're good and will still do work at BR5 and you can give them to your tankers.