Hmmm, well I guess it is not more effective, you’re right. I just went and looked at the numbers and by the end of round 6 the transport method would only yield you 12 units, while the factory method would yield you (assuming you use original 2 transports) 4 on round 2, 3 on round 3, 4, 5, 6. The method I would be advocating would require two extra transports to shuffle down to brazil, which obviously costs substantially more than the factory and only allows you to get 1 more unit there a turn.
I think I just have an aversion to having a factory around not doing anything later in the game, but in your case it would definitely be worth it. In every other case I would definitely suggest against a brazilian IC, but for the smallest amount of IPCs I guess the factory in brazil would have to be the way to go, assuming you just want to use the original EUS transports.