Robin in RD = HUGE Justice sense, depends on technolgy and martial arts than magic
Raven in Twi = Mystery, rare kind of a magical race, well read, etc
There can always be something interpretated into their personalities to fit another one. I always shipped Robin with Raven, dunno, but in the Titan series those two had a great chemistry which I could see become a base for a future relationship. In fanfics mostly ofc.^^