Picking an NPC weaponFollow

So I've read all of wiki on Adventuring Fellow and remade my girl.
Normally I've given her Fierce Attacker and a Great Katana, but then I was a Rdm or Samurai.
Now I am a Samurai / Monk and leveling Red Mage(wow I am repetitive on new chars) but also intend to solo/low-man all subs from 37-50.

Now my concern is: Do I stick with GKT even though I can't 2step Light with her as Sam(but I can Darkness with Monk) or is there another, more beneficial weapon?
I generally liked Gkt for the look and WS's. Now I am not so sure and I may end up making her a Soothing Healer type for Sam/Dnc solos...

I'm sorry, I can't help you much here from a real analysis point of view. My own best experience from playing monk (at lower levels especially) was that a Soothing Healer with a one-handed sword did me best. Her per-hit damage was negligible compared to mine, so I was relying on skillchains. Because WS of choice seems so random, having two low level fire ws (Burning and Red Lotus) meant the chances of me closing Fusion with Combo or Raging Fists were higher. Of course having the heals+hastes+status cures is a great boon for a DD, keeping you alive, saving you TP (if /dnc), and increasing DOT by maintaining haste and limiting debuffs.

Now, Clearite is 66ish and I have switched her to a "Trader's Siao" looking getup with a daikatana for little other reason than it looks cool. Even on fiece attacker I outdamage her by a mile so I just keep her on Soothing Healer and do my own thing.

Sorry I couldn't be of more help, we have read your question just some of us don't know the answer!

K