The game mechanic that has made the Divinity series stand out as some of the greatest crpgs of all time are the strategic choices you make to win fights with the various elemental combinations and the armor system in DOS2 really shat on that. Thus the game completely favors an all physical damage group. On top of that, control mages can have a much harder time than melee (especially warfare), as they'll need to chip the magic armor away, before beginning to be usefull to the team.' 'the current Armor system favors 1 damage type parties (either physical or magical), in order to maximise the damage output and the controls' ability.
If there are any 'essential' mods it would most definitely be Armor Based Saving Throws and Controls Are Back as I feel the armor system is completely flawed and as the description in 'Controls Are Back' says,
