I personally like the way it's handled at the moment. Having physical and magical armors separated offers more tactical decisions in and out of combat. The main problem I see here is the fact there are not enough skills increasing either physical or magical armor.
If more skills were improving armor, it would be definitely more interesting to build a tank in DOS2.
I would like to point out as well that the balance between offensive and defensive skills is not good at the moment in my opinion. There is a lack of protective spells and in the meantime offensive abilities are so powerful that sometimes you wonder why characters even bother using weapons.
