Your recommended team is pointless considering that Itaqua and Caspiel haven't even been released yet.
Also i don't think mordred is the desired soul so much as black propaganda is a necessary ex ability against ragnarok difficulty and considering that not a lot of people will have gaia a defensive soul will most likely be needed.

Ultimately strategy in this game is a case by case situation as not everyone will have the same KH and therefore will have to approach fights differently based on what they have.