Honestly, I'm not sure what you are trying to say. RDM will never ever compete with BRD, GEO and COR unless it's severely redesigned from scratch. I never heard of anyone getting a RDM instead of a COR and BRD. It's literally not an option from most people.
It's a completely different kind of support that these days is completely useless because MP are no longer an issue, everyone has haste and convert, etc. GEO could be nerfed to the ground and people would still not get a RDM. They would still get a GEO or a BRD or a COR.
The Job doesn't need a buff as much it needs to be redesigned or at least made more similar to SCH.