The only issue is I like Mitchell at 13 but I guess it's back to the wing for him.
Are you crazy? Mitchell's defence in 13 was abysmal at best! Mortlock originally played 12, then wing, then 13, and has played them all as a wallaby, but i prefer him at 13. Mitchell as a winger was ok, but no C. Vuna. Rooney, and Sipa, haven't stepped up (Rooney had a good game starting at 14 against the force I might add, but was an exception to the rule) Kingi has been better than both of them out of position in the back 3.
That all being said.... last week irrespective of jersey numbers, Mitchell, played 11 (in jumper 13) Gerrard played 13 (in jumper 15) and Kingi played 15 (in jumper 11) for the majority of the game. another one of MacQueen's tricks.
The big question is do we want to play 1 or 2 5/8ths? traditionally #12 is inside centre, and is a position where you run straight ball (well should anyway) and make holes, like Carter/Nonu, Cipriani/Mortlock, Carter/SBW, etc. But a lot more teams, especially international teams play #12 as "a second 5/8th" like, QC (Quade Cooper) 10, Gits/Barnes 12, or Cipriani 10, Huxley 12.
There are advantages and disadvantages of both, and the whole backline structure can change as a result. Given the form backline players are, (in no order) Phipps, Cipriani, Mortlock, Kingi, Vuna and Gerrard, MacQueen will look to have a team that works best for those players, and what other player/s can fit in there. Phippriani is locked in at 9/10 as far as i can tell, both have been playing pretty darn good there, and no obvious replacements.
Kingi, a scrumhalf specialist now, is the surprise packet, he used to play 10/12 (1st/2nd 5/8th) recently, and Huxley can as well, if Rod wants to give Kingi a run at 12, then mortlock to 13, and find another winger. otherwise if he wants Kingi at Fullback/wing again, I'd suspect Gerrard would play 13, mortlock 12, making a lethal centres combo, and Kingi, Vuna and one other to make up the outside backs)
The other winger/outside back is the odd one! with my pick on Mitchell, as he looked dangerous there week 2 and 3, and his defensive errors are less obvious. But I wouldn't want him playing majoritly at FullBack...
Below are my preferred options, pending injuries obviously.
9 Phipps
10 Cipriani
11 Vuna
12 Kingi
13 Mortlock
14 Mitchell
15 Gerrard
would be my pick, with the alternative as.
9 Phipps
10 Cipriani
11 Vuna
12 Mortlock
13 Gerrard
14 Mitchell
15 Kingi
or the conservative as
9 Phipps
10 Cipriani
11 Vuna
12 Mortlock
13 Mitchell
14 Kingi
15 Gerrard