My simple answer would be that I'd tell the government to go back to the drawing board. If you have the bill as it stands and you have no judicial discretion, it's not going to be an effective piece of legislation. It's not going to achieve the goals, as I mentioned.
One thing you could do is you could make it presumptive: for an offence proceeding by way of indictment, with a maximum penalty of ten years or more, the offender will be presumed not to receive a conditional sentence, or language to that effect. This would permit a court in exceptional circumstances, for example, with respect to the aboriginal issue, if restorative justice was uppermost in the court's mind, and the conditional sentence is, of course, a hybrid--punitive and restorative--to impose a conditional sentence in that case, notwithstanding the language of the statute. That's one way of doing it. You could allow the courts some souplesse, some ability to impose a conditional sentence, although there would be a strong statutory presumption against it.