basketball analogy time! (my favorite =) the NBA employs 450 of the best basketball players on the planet, and at any given time, the league is evaluating a few thousand more (out of hundreds of millions of basketball players, out of ~7.5 billion people worldwide). all the easy filtering is done. every year, the 60 most promising players are drafted. and because they're among the most promising, most of these 60 players should become regular NBA players. in practice, only 5-10 will do so in any given year, and you have no idea which ones it will be as they all look promising (e.g., laker kyle kuzma drafted 27th in 2017).
in short, once you get down to the 10-20 candidates you think will fit a given job, you might as well just draw a name out of a hat, work with them for 3-6 months, and re-evaluate. there really is no shortcut to this (not even for google).