I think you guys are making a bit too much out of a starting spot.
Until one of them proves to be definitively more valuable than the other, the allocation of minutes will depend on matchups and who's hot.
More than likely, at this point, Moon is going to be seeing those key minutes because of defense. Against teams like Philly, Boston, and Orlando, we'll need Moon out there defending Iguodala, Pierce, Lewis, Turk or whoever.
But if Kapono has proven to be hot, and he's hit shots all game forcing the defense to pay close attention to him, he's going to get the nod despite being a little behind defensively (although, as was mentioned earlier, he's not bad in a team setting. just can't lock someone down one on one)
It'll go on a game by game basis until one of them proves he's the go to guy, which may not happen at all. It's not like Sam has to plan allotted numbers of minutes for the two of them prior to the season.