I don't think you quite got the point. As long as the Czechs pump out a voracek, a pastrnak, a kubalik, a hertl, a necas or a krejci every few years, their A roster is going to be filled with very talented NHL players.no offence, but when was the last time czech made semifinals in wjc? 1999? so its not years from years for them, they have been bad at wjc for a long time.
Being mediocre at the WJC is only indicative of DEPTH.
You don't need a 100 NHL players to contend for medals in a best-on-best situation.
As for Germany, they have to continue pumping out elite talent for the next 10 years to accrue a sizeable pool of good NHL players. They only have Draisaitl, Stutzle and a goalie right now. It does look like Germany is improving, but overtaking the Czechs will take a long time.