Yes, I think he should marry again. Marriage is a beautiful thing. It's all what you make of it, that's life itself... Not sure what has happened in the past and really don't care to know becasue the past is the past.
Just take your time and make sure that the person that you are with is equally yoke along with you. Most of all keep "GOD" the almighty first... I think things will be okay. Just don't rule marriage out.