You can't.
There is a french general during WWI that pretty much established that ultimately human boiled down to four defining tendencies.
Smart VS Stupid.
Industrious VS Lazy.
And that therefore generals and officers, which didn't pick who they would work with should quickly ID which of which their subordinates were and task them accordingly.
People that were industrious and smart make for excellent rear officers or excellent troop commanders and will pursue their task with precision and pay attention to even the smallest details, ensuring proper placement for each MG nest, proper flow of supplies, etc… Those were fairly rare, less than 1 out 4.
People that are lazy and smart are however what you want for general officer, simply because someone industrious will simply drown itself into the details and fail to see bigger pictures. Also someone lazy will naturally tend to delegates things he's not sure he can do quickly to people more competent than him. He considered those people are the rarest, maybe 1 out of 10.
In the same way people that are stupid and lazy (that's the bulk of people) aren't worthless, you just have to assign them to simple task they can't fuck up by being stupid, their inherent laziness will actually encourage them do to properly (to not having to repeat them) and make sure they don't do anything they were not instructed to do.
However the most dangerous and completely useless are the people that are stupid and industrious. First typically they don't realize they're stupid, second their industrious nature pushes them to do far more than what was instructed, so their fuck up, unlike the stupid and lazy, will not be strictly limited to their assigned task but compounded.
You can't do anything with them, you have to either give them menial tasks or more likely give them BS assignments, posting with nice titles "liaison to something and something", but that don't really have work to do, etc… Those guys being roughly 1 out of 3 people.
Now you take that type of though and adapt it to modern day jobs and you get that nice chart.
Where do you think leftists are?
Yup, down right.
You can't do anything with them.