I respectfully disagree. QF needs to pay narrowbody FOs more than SOs as these roles are more safety critical and require significantly more experience than a SO.
The position of SO should be the lowest entry level position, attracting the lowest remuneration, just like it is with JQ 787 and VA 777 prior to Covid. From there you graduate to a regional turboprop or narrow body jet and so on and so on.
How it is currently done in QF where SO seems to be a highly paid role is unique within the aviation industry world wide considering you do virtually nothing……
And this is where QF management have dug themselves a large hole. If group was united and pilots had a career path they could move around types and could pay the SO a lower salary as people with experience could move into other roles and be paid what they really should be paid. However the problem they have now is people are leaving poorly paid experienced roles to take a SO position because it's the only way to get some career stability and get paid well.