The main problem here is that neither Powe nor PJ can really guard Odom. The good news -- Odom is generally irrelevant anyhow. Therefore, my guess will be that whoever starts, we'll still see Posey at the 4 early on.
I wonder what happens to the guard rotation in this case, though. Will we see Sam at SG, or more Tony Allen? I am not sure which option I like more, to be honest...