It appears that it is possible for a CFI, with a bit of time to kill, to re-write the aircraft checklist / pilot’s operating handbook, based on his or her personal preferences, with scant regard to the manufacturer’s recommendations. I agree with 411A about it being entirely reasonable for an operator to use the manufacturer's operating data. The manufacturer should know the aircraft better than anyone.
Anyway, my immediate problem, is that I'm renewing my Multi-IR next week and I now need to re-learn data that I thought I already knew!