I think Puma's point is more and more regulations mean you read and digest less and less (as a percentage of the whole).
In years of yore, AMFOs, or Air Ministry Flying Orders was a very slim volume that weighed less than the cover of one of the current JSP. based on AMFOs, Commands would write ASI or Air Staff Instructions. In turn Groups would right orders or GASOs.
One advantage was the orders could become increasingly focused on one gruop or type. The disadvantage was that an order written for 1 Gp might have had application in 3 Gp but never put in 3 Gp GASO.
The really important orders were in the Flying Order Book. This could be browsed in a few minutes.
As AMFOs were for the RAF the RN and AAC went their own ways which was why JSP 501 had Joint orders and single user exceptions etc.
As the OP says, may FOs etc now are so cross referenced for CYA purposes as to become meaningless. Some 30 years ago a sqn cdr on 201 tried to stem the tide but soon got swallowed up in niff naff and trivia.