The fact that Mort "lost his true name to time" makes me think he is significantly more ancient than Brogan's father would be. I like the idea that the two may be connected in story somehow though.
It is mentioned that Brogan uses an enchanted sword, and Mort's sword looks very similar. Perhaps there could be a connection there. Or they could be connected by some kind of prophecy. There could also be a more distant blood relation than father or son.