Every situation is different, but in Slafkovsky's case, you have a 17-year-old playing well in the Finnish league and for his team in the Olympics. It's easy to see why he overtook him.
The issue here is accepting or at least acknowledging that if it can happen to Wright with all that he did prior, it can also happen to Hagens. Both could and should still be very effective NHlers, slightly more optimistic with Hagens atm.
The big thing with Schaefer is you have to buy into the projection as an NHLer in terms of what he could be if everything hits. He's a 6'3 defenceman who skates like the wind and isn't shy physically, who's also offensively in terms of his production, very good. Maybe it's something I've grown to appreciate watching Toronto, but the importance of having an absolute horse on the back end like Doughty, Hedman, Pietragelo, Makar, etc.. is almost essential if you want to go far in the spring.