It was discussed since long, there are different opinions.
1. True, that's a disadvantage hardly to deny. But a mixed group of 2:2 for example could take advantage of the fact that most enemies have the two armors in different numbers. Two magical damage chars could attack the low magical armor melee NPCs while the physical damage companions deal with the magical enemies. Rangers quite often have balanced armors, but lower numbers in each.
2. I like it. It removes a lot of randomness from fights because only with such an armor system you can make reliable CC possible. I don't like that oil ignores armor. It's quite annoying and I shiver from the thought what would happen if more status effects would be similar.
3. I find it cunning that the AI positions it's fighters against low value armor targets. Why should a guy with lots of physical armor fight against your physical melee guy instead of using it to get to the much bigger threat of your ranged? A taunt would come in handy here, unfortunately it is blocked by armor. They should make oil being blocked by armor and the taunt ignoring armor.
4. I like it. It is a tactical play of trying to get the precious armor back. It's like healing but with more diversity.
My only gripe about the armor system is that it makes fights abit of a dps check since most status before armor doesnt matter, which team gets the enemy's armor down first auto wins the match with endless disables.
Well those disables aren´t all the endless, as you need two statuses to actually truly disable someone (shock+shock) and cooldowns are not exactly short aswell. Only knockdown works this way, BUT knockdown is basically only on battering ram+battlestomp, which is hard to hit if you utilize height advantage of any sort.
And for dps check - well, its not that bad thing, as it solves the problem of CC cheesing your way through game, you simply have to be ready to win that fight