Chipmunk,
Dykes will not play a standard halfback role as he tends to hold the ball in his hands longer. Therefore, he'd probably run past the 5/8th anyhow as he drifts across in attack hopefully picking up one of our flying centres or burty. So Wagon should only be there for defence and as an extra forward in attack.
After scrums, the ball would probably be passed to a winger anyhow or Hindy standing out of the scrum at 5/8th.
However, I agree with most that a creative 5/8th would give us heaps more options especially near the opposition's try line.