What subjob would you recommend, if not RDM?

I haven't done hardmode missions yet, mostly due to lack of a LS (like I said, returning player). Obviously some things will be difficult for RUN to tank, just like there are some difficult things for PLD to tank. I can certainly update more info once I do them, but this was more for the people who think RUN should be a DD or whatever (Despite the fact that, you know, they have no attack bonuses whatsoever).