TopTup, here's the thing.
I've worked in a few different companies, and all of them had their own SOPs.
More often these would be Manufacturers SOP's, with a twist. But sometimes they were widely different from Manufacturers SOP's, and were introduced because of some particular 'hangup' in that company. Perhaps a previous serious incident, or accident. Sometimes the differences were because the company had numerous different types in its fleet, and had tried to standardise across the whole fleet.
Mostly, these were good companies, with good training departments, and serious thought went into the design of their SOPs. Many of them made perfect sense, and were an aid to operational performance and safety.
Then you move to another company - and those previous SOPs are wrong Wrong WRONG!!
Very well - as you say - that is what you signed up to, and so lets do it 'their way'. No problem.
But don't fool yourself by thinking any SOP is monolithic and immutable. Clearly they are not.
Indeed, you don't even have to move companies to see this proven.
Ever seen an SOP that was Gospel one day, and Heresy the next?
We play the game, and do our best, but when SOPs become nothing more than a stick to beat each other with they become a threat in themselves IMHO.
As to the F/O who goes by the book and gets slammed by a Captain - I have every sympathy. Its yet another example of the dilemma created by blind rigidity.