I hated playing Cooper at fullback in defence and moving Beale to the wing in 2011 because it severely limited the impact of arguably our best player from 2010.
This is the reason why I'd either play Beale at 10 or play Beale at 15 and not play Cooper at 10. For everything Cooper adds when he is in the side, I think we need to consider how much we lose if we make Kurtley Beale defend on the wing.
Finding good balance in the backline is a difficult thing. I don't know that a backline that contains all the three amigos is our best backline.
The only two obvious picks for me are Genia at 9 and Ioane at 11.
If you consider we have the following potential players in each position:
10. Beale, Cooper, O'Connor, Barnes (and Lealiifano in 2013)
12. Barnes, McCabe, O'Connor, Fainga'a
13. McCabe, O'Connor, Horne, Fainga'a, Ashley-Cooper
14. Ashley-Cooper, McCabe, O'Connor, Tomane (let's assume Mitchell isn't a contender for 2012 and Vuna won't play for the Wallabies again this season particularly as more players become available).
15. Beale, Ashley-Cooper, Cooper, O'Connor
From these options, we have the current backline (for this Saturday):
Genia, Ioane, Barnes, McCabe, Horne, AAC (Adam Ashley-Cooper), Beale
Lots of people would like to see McCabe trialled at 13 and make into Morty Mk II. That backline could be:
Genia, Ioane, Barnes, O'Connor, McCabe, AAC (Adam Ashley-Cooper), Beale
If you're going to pick Cooper at 10, I think you want McCabe at 12 rather than Barnes or O'Connor. Given the form of Barnes in the last few tests and KB (Kurtley Beale)'s form at 10 in Super Rugby, I think it will be hard for Cooper to get a run at 10 in the Rugby Championship unless he has a blinding finish to the season for the Reds.
Personally, I'd like to see this backline given a crack.
Genia, Beale, Ioane, Barnes, McCabe, O'Connor, AAC (Adam Ashley-Cooper).
I think Beale is the most talented all round back that we have and the best sides in the world have their best player at 10. Having Barnes at 12 provides a genuine second five option who is also a strong defender. McCabe for crash ball and strong defence at 13. AAC (Adam Ashley-Cooper) has been really solid at fullback, is strong under the high ball and a good defender.