"Ultra-cheap" labor can't interpret technical documents. It can't improvise if a process is not working. It can't communicate with R&D. And toys are certainly not a technology.
And try to work on any technology with someone who doesn't speak English. Immigrants are flocking to the US for technical manufacturing jobs because the US school system keeps turning out punks who read at a 4th grade level and think the US never landed on the moon, but UFO's are alien space ships that need crop circles to navigate.
chinese and indian engineers are very smart. they earn alot more then the factory workers of course, but still a very low wage compared to US standards.
the only reason foreign nationals need to come to the US for engineering educations is because their own systems are not built up yet. In time, that will happen. As engineers there get older, they will leave industry and enter the higher education systems there - that will be the way they form their programs with trained engineers as professors. that's why we don't see many japanese engineers in US programs - they are moved past the phase of needing US degree programs for their own people.
The US high school systems turn out more than enough candidates for these fields, not everyone needs to enter them. The reason fewer are taking this up in college is because of the market dynamics of finding a job and wages in the field.