Unless Lattin improves dramatically, he shouldn't start at all. It would be disappointing if he did.
Admittedly, this is something that I have been banking on. He's a great athlete with a great motor, and if I'm not mistaken, he hasn't played basketball for that long. Nobody is a lock to dramatically improve over the course of their career, but if anybody was, it would be him. Spangler, on the other hand, seems to have pretty well maxed out.