Could Axis and Allies be "balanced" by weakening the US just a bit more?
This would be an interesting variation. I'm thinking you would have to remove all 3 IPC from Brazil. The timing of when IPCs are delivered has a huge effect. Early IPCs allow the Germans to build up faster and drive Russia back, put a nice force into Africa quickly, or replace one of their lost fighters that they usually lose 1st turn. Even so, losing 3 IPC/turn from Brazil might not be as much of a factor as 12 IPC early. 3 IPC is only 1 less US infantry. The US threat builds over time, and is mainly in the form of retaking western Africa, threatening Europe, or reinforcing Karelia. All of these sap German resources. By turn 4 when the US had lost 12 IPC from the Brazilian removal, the US forces would already by doing most of the damage they could be doing, and the German lack of 12 IPCs would already be showing in the inability to expand as quickly. 

Why not just whack the US first production by 12 IPCs? You could justify it as a late start into the war because of Pearl Harbor and taking time to mobilize its defense industry. (Of course, in reality, the US defense industry was going quite heartily, supplying the Allied forces).