It definitely wouldn't be a traditional halves combination but providing Cornish actually proved to be a good first grade standard half (which I have my doubts over, but anyway) then I think that spine could work as a whole. Obviously Cornish and Williams would have to split and play left/right but you've been playing your halves like that for years now even when you arguably shouldn't have so that won't be an issue. Neither of them - Cornish in particular - have great creative games but with a hooker with a halves background (McCrone), a ball-playing fullback (Milford) and a ball-playing second rower who could take the ball at second receiver on the right (Papalii) then I think that could come from other areas. Each would manage one side of the ruck and combine to give the side direction, while the creativity would come largely from one pass wider with Milford/Papalii or closer in towards the middle of the ruck. I'm a bit of a Cornish sceptic myself so I'd have been leaning towards just letting him go and looking towards a Williams/McCrone or Williams/Milford combination, finding another hooker or fullback option, but if he stays and does turn out to be a good player, I don't think his similarity to Williams is really a big barrier.
Cornish is definitely the outlier. We still have set plays that rely on the traditional halves setup and Williams is not as good second receiver as he is first receiver and I see Cornish being the same. Robinson could also be considered for a halves spot with Milford moving to fullback. Could even be something like: 1. Milford 6. Robinson 7. Williams 9. McCrone The other thing to consider is that Wighton is also a natural 6 and could very easily play in the halves, not sure if his kicking game is up to it though.
