If all occupations cooperate and allow greater competition in their respective fields, then the net wealth effects on the economy are positive. If one occupation blocks competition, its members may benefit relative to other occupations, but there is no reason to assume that only one occupation will be able to defect, and encourage a policy decision that benefits its members.

One of the ways to counter the inevitability of actors making rational decisions that end up making everyone worse off is through the setting of effective public policy with an eye to aggregate benefits.

I think it is very safe to assume that the point of funding engineering education was that engineers' work is valuable to society, not that people who can make it through intrinsically merit certain salaries. If acquisition of talent through immigration is another channel, so be it.

The idea of education subsidies is also interesting to consider. On one hand more people are able to choose the career, so the skills are less scarce, and salaries are lower. On the other hand the increase growth in the community of trained people allows for greater sophistication, cooperation and specialization, which leads to more valuable output, and higher salaries.