I can't even count how many times I've come across the fact that the bad guys have multiple wands and the good guys one! Another is that Pureblood children can practice magic at home before and after starting Hogwarts while Half-blood and Muggle-borns can't. There are so many differing reasons for that if ff that I won't even bother to try counting! Don't even get me started on the moronic idea of Aruros fighting DEs with minor spells while facing deadly fire! That's like sending troops into battle with cap guns while the enemy uses AK-47s! But then Fumblewhore always had his own little plans running behind the scenes.