I'll reiterate again. The RAAF QFI training and flying is polar opposite to airline sim instructing. An ex RAAF QFI is by far capable enough to be a Grade 1 instructor.
Perhaps Captain, perhaps. I have flown with a few RAAF pilots over the years and their skills have been exceptional but remember the old adage"
"Those that can do, those that can't, teach" - Bernard Shaw
Often thrown around in a derogatory manner, the adage still bears thinking about. My observations of exceptional pilots is that in fact they are poor teachers because their standards and expectations are too high. They cannot understand why others aren't like them. They resort to demonstration when the hapless student is incapable of either understanding or observing at the rate the instructor expects.
Give the bloke his grade 1 instructor rating, give all ex RAAF pilots who have taught one too. In that I am in full agreement, but wether they will actually make good ab initio trainers, the market will have to decide. Some no doubt will, many already have, some will fail miserably and be generally disliked. It's always been thus.