Townsend is slow, always has been. The reason he works with the Cowboys is they have Dearden, plus Drinkwater at full back who plays more like a quality halfback in attack. He provides structure and that's about it. You'd have to add a lot of speed around him for it to work. People talk about ambition and then suggest signing a 33 year old (which he would be next year) is ambitious? Ambitious to me would be spending some cash and signing Croft.
However, there's a real shortage of quality halfbacks at the moment, NRL included.
The Dolphins trio of O'Sullivan, Milford and Nikorima might be worth looking at. Katoa will be the Dolphins 6 for the foreseeable future, and the other three are fighting for one spot. Nikorima has done much better than expected at halfback, O'Sullivan was going well before he got injured, and Milford has played OK once he got fit. But only one of them can be first choice. Milford might fancy a change of scene, but would be a gamble as to whether he would put his heart into it, as he's generally floated around aimlessly for a few years now. I like Nikorima's style, and I think it would suit SL.
The only other player I can think of is Jack Cogger at the Panthers. He's done well as a reserve for Cleary, and is unlikely to be picked up as a starting halfback in the NRL. He might be interested in coming back to England if his alternative is reserves most of the time.