The best solution about companions is to have 5-6 origin character and many more usual companions, that are just companions as in the old BG. Only one quest and they come with you for any reasons.
I don't really care that the companions quest line is 4-5 steps if the quest is interresting and take a few hours to play (BG2).
Origin characters are designed to be the main character (that's the concept). Every companions don't need that. Quality companions doesn't mean origin characters...