Draco and neville would know this. Also the Potters are not recognized as a pure blood family where as the long bottoms and weasley are. That is the list Draco would honor most.<br/><br/>((Forgive me posting from phone))<br/><br/>Also, the reason Draco was informed to become Harry's friend was because Lucius and the dark families believed Harry to be the next dark lord. Draco changed his mind when he decided to align with the weasleys.