If a player is getting double teamed at the 2, does the 1 spot benefit more or the 3? And if the 5 is double teamed, does that mean that the 4 now has an advantage? Or is it just totally random.

I don't think you can pinpoint the exact player who benefits from a failed doubleteam. The risk in the doubleteam is simply whoever you attempt to double may still make the shot or dish it to anyone else who then has a greater chance of making the attempt due to the doubleteam. Breaking it down to what player benefits may be just trying to look too deep into this. I'd say it's more of a random thing.