Derfred: I agree with your suppositions. There is not black & white, right or wrong; sometimes. I've flown for differing quality C.P'.s Therefore some were excellent, some less so. Same a/c very different SOP's; all approved by both various XAA's & manufacturer. No SOP's were without comment. I can take a selection from 8 operators and arrive at an excellent set of SOP's, but none of them had the straight flush of SOP's individually. And all were reluctant to listen & learn from others. As a result their pilots, who were home grown or long servers, believed that here was the be all & end all of how to do it. It was most frustrating but one had to live wit it.