I agree with GB2. Balance with. Other mature democracies have something similar and it works. Not unlike BALPA in the airlines. Someone to represent outside chain of command, advice on law, working hand in hand with management. Highlighting areas for improvement and of concern. Even, maybe insisting on minimum levels of equipment.
Seems to me the most contentious area would be "military risk" on ops. Something like BAFF has been discussed in the past, but never as seriously as now. This can only be because of a general feeling that leadership at high levels is not there. One would imagine that if the chiefs got back to fighting tooth and nail for their men then talk of a need for BAFF would melt away.....