I have seen a lot of criticism towards the current state of the armor, but not a dedicated thread, therefore I start the one.

One of the most discussed problems here is the existence of 2 types of armour on your foes - physical and magic, which forces to build a character as well as the entire party around one specific type of damage, therefore limiting choices.

To solve it, several changes and additions may be done (I will start with the most radical ones).

1) Merge two armour types into one.

2) Let reduce both types of armour at once: whenever physical armour is reduced, magic armour is reduced as well for 50% of the damage dealt.

3) Make it reasonable to remove the both kinds of armour: damage to a target with all armours destroyed increases by 150-200%. Enemies don't suffer from this debuff if they don't have one or both armours by default.

4) Make more enemies with one armour specialization - currently most enemies have equally strong physical and magic armours. If 35% of enemies had a very low magic armour and another 35% had a very low physical armour, there would be some space for proper targeting and therefore a mixed party would have more ground.

5) Let classes deal both kinds of damage from the early game.
Currently you can find some weapons with like 20% bonus to damage as magic damage; currently this is the least useful weapon feature because a warrior's target will anyway die before it's magic armour is consumed this way. Instead, let some weapons have an ability to switch to a magic form. For example, you find a sword of lightning with 10 physical damage and an ability "form of lightning". The ability costs 1 AP and lasts forever until it is toggled back - even after the battle. After you enable the ability, the damage is 2 physical plus 10 air; now you "form of lightning" is replaced with an ability "physical form" which allows you to return the sword to its normal state.
Now the only intellect-based physical class is the Necromancer. As for the others, let them have a couple of spells dealing physical damage. And give some magic damage skills to Necromancers.

6) Skill crafting. I hope the Devs have already found a solution in skill crafting, and it will be possible to create skills that turn 100% of magic damage into physical one and vice versa.

In my opinion, the best solution will be a mix of items # 4, 5 and 6 as they have minimum impact on the game design fundamentals plus # 3 because I it would add to tactics.