The Germans can be demoralized like any other team but the key is to score on them quickly. You can wait on the Germans to come at you, you have to attack right away and keep attacking for the whole match!
Germany's Mario Goetze scores in extra time to defeat Argentina 1-0 and win the World Cup championship in Brazil. Ref. CNN
The Germans newspapers about the joke towards Argentinians they said (Translating):
As of today 17 July, 2014, FIFA ranks the German Football team as Rank 1 (+1) in the FIFA World Ranking.
Generation Change: Soccer mentor gives future stars plan B
Angelo Daut, Copyright: Mohammed Abugeth
Some of the young soccer stars Angelo trains in his spare time go on to become big stars in Germany, like national player Mario Götze. For Angelo, though, it's important that they learn to become more than football players. Ref. Source 2