This seems to be, from what I have observed over the years with Roy at UNC, the correct answer. I also believe that Roy's stubbornness would quickly fade when he measures what Zion does for his teams. He is very efficient and also brings a lot of energy to the table. Right from the opening tip. Its good to have that energy to start a game.
Williams recruited Zion for years and before duke, I think. He's knows exactly what Zion brings to the table and would start him regardless.. He started White over Seventh Woods from day one because White is that much better. Same would apply for Zion.
Little is different because his high ranking and draft projection is more potential than skill at this point in time. Of all of the top ranked guys 1-5, he was/is the most raw, but his ceiling is just as high or higher.
But I agree with you that Carolina needs his toughness and energy from the tip.. He needs to start.