What is the difference between Macbeth's army and Malcolm's army?

Macbeth's army acts more out of fear than loyalty. Macbeth has become so evil that nobody would stay out of love for him, or even loyalty, because he is a terrible ruler. Malcolm's army, on the other hand, believe he is the rightful heir to the throne and would give their lives to see him made king. There is no stopping Malcolm's army; Macbeth's, on the other hand, would just as soon abandon him as stay.