JJbenedictis, you're absolutely right, of course. But while it's not a lottery, there might be considerations that are so nuanced that it might as well be described as luck. Things like two submissions being very similar in some specific ways, or maybe the trait of an MC just rubbed an editor the wrong way for some personal reason... who knows. In any case, it's mildly interesting to consider the general odds of publication.
On that note, assuming 5 people get contracts, which I doubt is guaranteed in any case (could be lower or higher), the odds would be 0.7% if they're picking from both AR and SC pools.
It would be interesting to find out if AR is planning to focus more on epic fantasy, and if this is a trend away from the urban fantasy and steampunk trend. Personally, I'm looking forward to reading one of their forthcoming S&S novels (The Hammer & The Blade by Paul S. Kemp). I admit, I'm an epic fantasy junky, but it's interesting that whenever I see someone reading a book (whether it's at the mall, or at work, or just at a bus stop), about 1/3 of the time it's epic fantasy.