The more engineers you can sample from (in absolute number), the better (in absolute goodness, whatever that is) the top, say, 500 of them are going to be.
Does 5x the number of math graduates increase the number of people with ability like Terrance Tao? Or even meaningfully increase the number of top tier mathematicians? It really doesn't. Same with any other science or art. There is a human factor involved.
Suppose there's more than one. Then sampling from 5x the number of people increases the average number of him that you get (by about 5x).