It probably works for teams that don't have a bunch of tradition and great leaders(especially recently) to follow. Set some extremely basic rules, get everyone on the same page right away.
All that Holland does and requires is basically another way of doing the same thing. He just does most of his "mental tests" pre-NHL, so by the time the players wear the Winged Wheel they're molded into the right shape already. Not to mention the extreme collection of leaders we've had for a very long time now. Having rules for beards and numbers would be superfluous here.