I don't think you'd have to have two environmental auditors. It is true that if the majority of environment and sustainable development performance audits and the continuing work on the sustainable development strategies were done by the separate office, then the AG's office would continue to look at environmental issues that impact on all the other government activities and programs it audits in an ongoing way.
I don't see that being problematic. Two offices can work together and share out the work in that way, with one being focused on specific environment, sustainable development issues, and the other one looking at where there are environmental issues in transportation, or fisheries, or northern development, or other program areas.