Well, I didn't take pictures of the tactic, but interestingly enough it was primarily a result of my DMs.
I had a DLP(s) on the left and a BWM(d) on the right, and the AMC tended to sit on the right hand side. I tried swapping the DLP and BWM roles, and this caused the AMC to sit to the left much more, as I had hoped.
That said, the shift was not as dramatic as I wanted. The AMC has a tendency to drift onto whatever side of the field the ball is on, and the ball still tended to be on the right-hand side quite a bit...I think because of an IW who tended to make himself available for the ball much more often than my IF(a). So the ball would frequently be played CD -> RB -> RW [IW(s)], and then the AMC would have drifted over to support the RW, defeating my goal of using the AMC to play the ball over to the left wing.
So! I did end up moving the AMC to an AMC(L) - I'm onboard the asymmetry bandwagon, and it's working pretty much exactly as I hoped. Tough luck for my right winger though - his job just got a whole lot harder now that he's got very little support...sorry bud! It's for the good of the team