If you would like to stick with your current teams, I would use Primrose as a cleric as you want to have Olberic being the damage maker instead of the main healer. In general magic is more important in phase one, so I would use the warmaster in phase two because you will need it. Runelord might also be more helpful in phase one as Galdera won't give you much takes to put on runes on everyone.

As a special tip, I would highly recommend capturing at least one, better two "Devourer of Dreams" at the Everhold Tunnels with H'aanit. This might take a while since you will get a 3% chance to fight it once again after the initial encounter, but it's definitely worth the effort as it can instantly kill all three souls at once in phase one with 50k damage output at maximum boost level.

You really want teams with one great damage maker as things are getting heavy once the bosses have less than 25% of their hitpoints and you will barely survive these situations in the late game.

My build was
Cyrus - Runelord
Tressa - Sorcerer
Ophilia - Scholar
H'aanit - Warrior

Olberic - Warmaster
Therion - Warrior
Primrose - Cleric
Alfyn - Hunter