I’ve known some pretty simple engineers in my day.
But I think you just like to be a willful idiot here. As that chart shows, all kinds of skilled workers *average* below 100 on IQ: machine workers of various types, carpenters and other construction workers, assemblers, plumbers, auto and heavy equipment and other mechanics, electricians, clerical supervisors, farm laborers, truck drivers and freight and materials handlers, etc.
The vast majority of our population could well be employed without are scrambling to bring in mass no-skill jobs from third-world countries. (We just need to get the illegal third-world immigrants out!)
`All I am saying the chart you posted is ridiculous. It has no legend for Pete’s sake.