"Surely it is in these sort of exercises that the true value of simulators can be realised"
Very true. And if airlines were run by experienced pilots, there'd probably be as much simulator emergency training as there is in the military.
But airlines are run by beancounters - and they won't countnenance anything which takes pilots off the roster unless they're compelled to. A mate of mine in SirRB's airline told me that he made the same point as you, to be rebuffed by some suit who said "If reducing simulator times means that we might have an accident, well, that's what insurance is for".
Barking mad!!