It really feels like they split the two parties to the wrong targets.
Han's party has an archer, a spear and a powerful mage, all great picks for defending walls.
Edith's team is all melee and with a thief and a guard both 3 stars, they are an amazing choice for quick movement to a target and great at defending.
But story wise Han has the better overall team and needs to do the more story like part of the quest.