To turn in work of professional and skilled caliber, to do so always ahead of deadlines, and to be easy to deal with generally.
A person only offering one is not providing enough to make their employ worthwhile or long-lasting, while the chances of someone realistically offering all three are extremely rare. So, the idea is to look for somebody what can comfortably guarantee any two of the three anchors. For example, a person may only submit average-quality work, but if they are reliable for at least that much and are easy to work with, then they are employable. Or, a person might be notorious for blowing schedules, but if they are always friendly about it, and their end product is always outstanding even though late, then they themselves are worthwhile.
But no psych test in the world can guarantee with 100% accuracy exactly how people might work together. Too many variables and too many subjective variables.
I used to put down the leaders of big businesses for the various screw-ups you read in the news, such as the 2008 financial crisis, Carly Fioria destroying Bell Labs and nearly destroying HP, the recent meltdown at GE, the 737 MAX scandal, etc.
Over time I realized that incredible screw-ups happen all the time at small businesses (say a small-town general store) or medium businesses (say a venture-funded startup) If the people who ran big companies screwed up as often as the people who run big companies, we wouldn't have any big companies!
You might not need a 10x salesman to be a 10x developer, but the failure of any part of the value chain can multiply the value of your work by zero!
There probably is some way to measure the pathology that I mention, but it's not going to be superficial or "magic".