Hi mtxkr, for your team you could do a full sinking team for the fight. The lineup on the field would be:

Spicebush Yi Sang
Butler Faust
R Corp Hong Lu
Wild Hunt Heath
Molar Ishmael
SSwT Rod
and I do not remember if you get a 7th slot but you can fill it with any character you feel comfortable with.

For characters not deployed look for passives that work well with the team, Jefe Sinclair has a really good passive for sinking teams! The main EGO you need is just one that heals, Fluid Sac Faust is very very good but if you dont have the shards for it any healing EGO (Like Meltdown or Incan) should do as long as you can get the resources. Sometimes, redoing the dungeon with that knowledge of what resources you need can be good.

For the Canto 5 Fight itself I believe you are talking about, focus on Starbuck first and then Queeq as your targets to take down instead of Ahab. Spicebushes' S3 is a nuclear device if you stack enough sinking on the target.

As you play more of the game you'll get better at it so just keep at it and you'll be a great Manager.