Of course it would have been easier if I had bound to the 'Commands' path in the first place. This is what happens when I upgrade from an older version (but I do need that Tables functionality).
Anyone who has a similar problem as I had just remember to bind the DAtaCOntext of the RibbonMenu to 'Commands', as in the below:
Snippet
DataContext="{Binding Path=Commands, ElementName=editor}"