DW summed it up pretty well. Innocent shut down the casters shutting down all support.
OP Bow aside, Andante's team is a lot more optimized than yours DW. Multi element absorb with a lot of synergy between each unit. Really good stuff.
Ninja
Barren's call on Hidden + Platina is better than double platina since it should do more damage than double platina proc with just base damage.
Dual Cutter + Platina + Concentrate
Hidden + Platina + Attack UP works too.
Use as much JP as possible in passive abilities since it's rare to get your accessory stolen. Twist Headband, Green Beret, or Black Hood would also work better than flash hat too.
Archer
Ice Bow healing imo is best with Jade Armlet since that accessory is immune to stop. The ninja has salty rage so I'd recommend switching to Windslash Bow. You get a spec that is also wind based, and does a set amount of damage. She'll also be able to heal the chemist since he has defense ring.
Chemist could probably go with Basic Skill, Attack UP, and a Gun and get the same results without the faith. Throw Stone = Sinkhole. Gun + Attack UP = Comet since it hits 100% of the time and is WP*WP. If you go with that set up go with Green Beret or Thief Hat.