New to the game, although I did KS both of them.

Playing on classic mode and mostly interested in the story and some fun, interesting combat moments. I will have time for one play through only so I want to see/do as much as I can in one go of it.
Main: Fane (wizard)
Ifan: Wayfarer
Red Prince: Fighter
Advice? Who for #4, leaning towards Lohse from reading recommendations but I also think Sebille could be fun, Beast as well.
Right now I have Lohse in as an enchanter. So that's 2 physical and magic which I understand is ok to do.
So who is better for the story for a 4th?
And, do I need to hardcore theorycraft my characters on Classic? Or can I just kind of "go with it"?
Thanks!!