Dancer/Bushi might also be good for the same reason (and I can't think of a better alternative for Dancers, since I didn't use them much).
Nightseeker for dual wield is the way to go if you plan to use Trick Samba or any kind of ailment procs (which includes Dancer's stun skill, Mist Dance). With normal attacks they can hit up to 8 times in one turn.
Dancer/Bushi is good for Beat Dance party but I it never seemed to me like a good build in a more orthodox party because in that case your Dancer is probably either a healer or a hybrid damage dealer where chases and stun procs are very valuable and the damage of the dancer herself is secondary to the damage generated by other party members as a result of the dancer (as in, focus on skills like Attack Tango, Trick Samba, Sword and Mist Dance, and Refresh and Freedom Waltz). Of course, Dancer is probably the most adaptable class in the entire game so if you can make a Dancer/Bushi work, more power to you.
I'm guessing Medic/Arcanist doesn't work as well as the other way around due to the specific class skill right? Would using Wufanbe good or would it be better to start from scratch?
I guess that way I can get a runemaster in which I've never had.
Any tips on subclasses?
You can beat the postgame boss with Medic/Arcanist, so don't worry too much about that vs the reverse. Just be sure to load your M/A up with luck stat boosting gear to make the bind circles work better.
I used a Fortress/Nightseeker/Dancer party for 100%ing the game and the N and D make a good combo. Dance buffs turn Nighseeker into a death machine. Once attack buff is active and the enemy has an ailment, use Trick Samba to generate lots of extra attacks from the Nightseeker (with D/N dual wielding, you almost always get all 3 chases from Trick, and when the N is chasing on an enemy with an ailment, those basic chases are big damage).
I have not tried a party with a Landshark and a Nightseeker together. The two just don't seem to have good synergy on paper, and I'm not a fan of snipers in EOIV when Nightseekers and Arcanists can shut down packs of enemies so much more efficiently, and then N can do absurd damage on top of that. Snipers to work well with L for chaser procs, but if you're feeling like you're low on damage I would definitely say consider a Nightseeker...they start squishy but once you get Venom Throw they become gods in random encounters, and by the time you're at endgame, they're doing tens of thousands of damage in one turn with Swift Edge and Follow Trace.
P.S. The trick with Squall Volley is that you need to leg bind them first. Leg bind = no evasion = 100% accuracy.