Given how long Farrell has been used on the left edge I don't think it's fair to expect him to move into the middle and for him to have the same effect immediately. At present I think he's best kept on the left edge because he's in outstanding form and that left edge is our best attacking weapon. Long term though it might be worth a look. If Greenwood can regain his early season form next season he's a big threat out wide and that's when trying Farrell in the middle might be worth a shot.
Faz has a good all round game and decent hands. He may have thrown a pretty horrendous long pass out at one point but even O'Loughlin has thrown his fair share of those. It's just a case of seeing what works and seeing what works takes more than one or two games. For the time being though Farrell on the left edge is our best option, Isa is playing some of his best rugby on the right and Smithies is our first choice 13 and until Greenwood starts showing some form there's little point in moving anyone around.