Well the thing about Majestic that gives him more of an advantage vs Magic than say, Supes, is that he has the ability to manipulate matter/energy at the sub atomic level. That in essence makes him at least a class C (I totally just made that up) reality manipulator.
So combine that with the fact that he doesn't have a particular vulnerability to magic, and you have a more favorable match up for Majestic vs Loki then Superman would have vs Loki.