Rolf is great in RD. Marksmen is the best regular class in the game. The real problem is that there is only one weapon worth using for said Marksman and three archers. Now one of them is a member of the Dawn Brigade so he's right out and yes, it comes down to Shinon and Rolf. Both have very similar stats. Just pick whichever one you like more.
Meg and Fiona come too late to be any good. It's true.
Aran's biggest problem is that he looks like he already took his damn turn! Who made him gunmetal?
My main issue with Rolf is that you get him at the same time Shinon and because both of those dudes turn out great, I would rather just go the easier route and use the one that's a higher level.
I've ran into that problem with Aran a few times lol