Currently ordering is done on FacetedMethods, and contributee actions are grafted onto the end. Also complicating matters is the ObjectActionSet, which groups contributee actions according to the service that contributed them.
First change is to remove ObjectActionSet, and have everything flattened. Second change is to rework MemberLayoutArranger such that it acts upon ObjectMembers rather than FacetedMethods.
At same time, suggest retire the old "actionOrder()" supporting method.