What makes them smarter in general then anyone else? A coach do not become coach because his awesome skills at taking out the right players, he become coach because maybe education in some coach like program, having the right connections etc. He is probably better at training and coaching then most normal people are. But taking out the right players has nothing to do with it with them being the coach.
But with that said, you are probably right that when it comes to junior players, that many that writes here have not seen them at all, but it is not like it is the first time coaches in all countries at all level and all kinds of sport make horrible just horrible decension when it come to who you shall take out in a team. Many times it absolutly feels like they are overanlyzing it.
To me hockey is very much about momentum, and you keep that momentum easilier if you have skillfull players in all the lines and all the d-men pairs, so you just can keep on pushing. Otherwise we would see far more upsets, because even smaller nations can many times have a couple of really good players, what seperates them from the big nations is deph.
But maybe players like Garland would sucks I do not know, but I would love to see him.