I think two different things arise from the initial post. ROEs and tactical freedom are completely different.
The ROEs would be changed at ministerial level i believe, tactical freedom all the way down the chain.
From my observations of ASW, the Americans and their P3s had very little tactical freedom and always ran by their playbook at the expense of loosing the target, then Nimrod fleet was allowed more freedom as long as you got the right outcome, you might have to answer afterwards if the reverse were true. Our tactics manual was guidance, very little direct orders in there and that suited the way Brit forces operated.