Good round up www.
The Farrell to 12 thing was made crystal clear on the Lions tour where the Farrell/Teo style 10/12 left the rest of the Lions backs without the opportunities that seemed to arise with OF at 12. Obviously having a really well matched 13 in Davies helped - but the key change was bringing in a "flexi" 10 - and England could easily have looked to play the Lions 12 and 11/14 with JJ and Cips and Dobbie and Brown.
But like in the video I posted - its like 100% on a shit or bust opening that if thwarted challenges the ability of the team to think for itself.