It's just as shayuki said, BLM will deal more damage than RDM, period.

And it's supposed to, RDM only casts 2 secs spells and then has a instant cast skill, giving him a 3 seconds window to move around and reposition. RDM also has a physical buff for the PT, a pretty powerfull heal, and a ress who can be easily insta casted. If RDM having this level of mobility and utility, while also having damage at least on par with BLM then the RDM class would be completely broken.