Hugmonster,
CAP371 IS the work of scientists, pilots (BALPA), etc. The problem is the scientists cannot agree on what CAUSES fatigue or how the body's sleep function works, hence you get different FTL rules around the world.
In an ideal world, every airline around the world would work to the same FTL rules and have the same crew ratio per aircraft.
As for audits, I can vouch we have realistc audits not only by the CAA but our own internal quality department.
As for realistic rostering, the CAA stressed this in NTAOCH 6/94. A lot of CAA audits around 1993 and 1994 looked at the rostering practises of airlines.
What it comes down to, is that all rostering and crewing staff, should have formal training in Human Factors, especially on the subject of circadian rhythms.