A mage knight is a mage who focused on combat magic. They are regarded highly in most societies that are built on colonization and domination. It is a combination of a political and military title.
I have to acknowledge that Fedran is still a violent world and combat is a major part. Not to mention, I'm writing a world war where knights are heroic in the eyes of the winners and villains by the lowers. The glorification of being a mage knight is important because eventually it drives a lot of the people as they enter into the war.