there’s a simple reason not to put an IC in brazil.
If britian doesn’t royally screw up, they should build the SA IC, and coupling that with the fact that it would take a few turns for both u and germany to actually engage, the IPC’s you spent on that factory and any units you built there would be better off used to take the fight into Europe or to combat Japan in the pacific and keeping them off US soil.
All in all, it’s Britian’s job to build the units in Africa, while the US just throws attacks at the Med fleet and any German land units on the continent. The US shouldn’t be responsible for reinforcing africa via Brazil.