Wow this has to be the most interesting piece I've seen of Saint George. Just Wow! The emotion and the depiction of this moment is just breathtaking that I can't stop looking and analyzing it's deep sentiment! Very good job! I applaud you!
That's how Remarque could have probably seen this. Apart from that, people have always been wanting to personolize evil as something alien and scary as dragons, savage beasts etc. These beasts are not animals, however. They are sentient beings but depicted as ultimately malicious. Exactly the same approach is with depicting enemies. It's a very comfortable approach for avoiding responsibility and advocating hatred. So the dragon is somewhat an advanced version of scapegoat and an image of the enemy. The bad thing is that such an approach in most cases becomes mutual, almost completely dominates reason and prevents any mutual understanding. So in this situation St. George could have hardly done otherwise. Suspiciousness, xenophobia and hatred are almost universal and are very strong feelings dictated by the self-preservation instinct. On the one hand, they help an individual to survive. On the other hand, it's hard to supress them even when they are completely unreasonable. The worst thing is that these feelings are abused a lot. Sometimes it's only when one kills and sees their victim's agony, sees that their victim is not that different from themselves, one feels, if not understands, what a horrible thing they have done. It's tragic even in "kill or die" situations (as any such situation between sentient beings is a result of a chain of unreasonable actions which could have been potentionally prevented). That doesn't happen too often though (or there wouldn't have been so much wars and cruelty in the world).