NT football is more like getting together on a camp, having little time for actual tactics and then going on from there. There's no time for understanding the exact ways, either from the coaches perspective and even less, the players perspective. Some of the players just take more time to adapt, some of the players are more versatile. It depends on the player, but saying Lewandowski or Zlatan failing at international level is just BS. Atleast they never had the competion and they always made the NT, where other bigger nations had the competion to bring different strikers.