Good point, think of it like going it for a job, like Operations Manager for say Red Stripe, what you are doing is trying to winnow down the competition so you get the best applicants, first thing is you need someone with an engineering degree, mechanical would be great, ie would be ok, MBA would be great, experience in beverage operation would be critical, proven results at multiple locations for significant periods essential, awards a plus.
Same with defensive midfielder, proven experience in tough foreign league preferably Epl, la liga or serie a,if not championship, mls or Scandinavian leagues, proven defender, proven interceptor and high work rate, durable as evidenced in number of games played per season and number of games started. Proven goal scorer and attacking threat and excellent passer of the ball. Team player and leadership skills essential!
How many people could fit that description, if we were to do that for each position, we wouldn't see some choices of babies out of cribs playing in critical games or unproven players been put in tough positions where they have no business being, but as you say, good tool to isolate the best in the crowd, once that is done then it is all about chemistry and desire.