USA has a 1500 hour rule for FOs. Before this the limit was 250 hours. Many training people I spoke to said when they still took 250 hour people, many washed out in the sim. It wasn't the flying of the sim they failed, it was situation awareness and being able to talk to ATC, run a checklist and make critical decisions all at oncw. They could not imagine taking someone with only 50 odd hours in a real airplane and then expecting the sim to make up the difference in these critical areas.
If really worked they said, the military would train that way.