American ROF should be ludicrous as you have 6 (Mustang) or 8 (Jug) MG's firing at the same time. Even though the .50 cal bullets did not penetrate even a tank's top armour, they were nevertheless used on tanks because the sheer volume of fire meant that at least some shells had a realisting chance of going through the air intake / radiator grilles on the engine deck and doing some damage.
Also, now that I see more and more screenshots, the Friedrich should really lose those Gustav's gunpods. If it causes an imbalance, so be it, add another 109 into the mix then.
Yeah, and even if the visibility was several kilometers, setting the convergence farther than 150-200 m is pointless as you are not going to hit a fighter-sized wildly manoeuvering target at that range anyway, or even if you accidentally hit, you are not likely to do much damage.