Fenrir and Diablos, Prime FightsFollow

I solo'd Fenrir Prime as a lvl 90 SMN/WHM. I'm not sure if your smn is that high, and I haven't tried on any other jobs yet so I can't offer more than that sorry. I just stuck Garuda on Fenrir, did pred claws, and put myself at max distance (Fen runs very fast). Then repeat when Garuda died. Took about 4 or 5 Pred claws for Fenrir to go down, and I have very low smn skill (250ish).

I'm getting close to this part too.

To be honest, Summoner used to be my main, but when I went to rejoin, I had to make a new account. All I want is my Summoner back. But as every good Summoner knows, it's a pretty tough job to start up. I leveled RDM to 50 for the obvious subjob, (I have been having wet dreams about having Convert). But then I realized that it's a bit difficult to make enough money to get the spells for mage jobs at low levels, unless you already have a high level job. It's a bit biased against new players wanting to not be completely gimp, but I know it's because everyone and their grandma has a level 90 job that they can make money from Aby on and buy whatever they need. So now I'm leveling DNC and THF to be my solo/farming jobs.

My question:

Is it possible for a level 90 DNC/THF, (or even THF/DNC, I'm not picky), to solo Fenrir Prime and/or Diabolos Prime? I've been told that two DNC can duo Fenrir fairly easily, but I have a pretty odd time-zone constraint where I'm not online that the other English speaking players might be. So I'm wondering if I can get all of these things by myself.

What do you guys think? Is it feasible?