Intro
GU devs have released Armor 2.0 onto the PTR (test branch of the game). The big mechanic is that armor will degrade when creatures take damage that lowers its health. The problem this is trying to solve: armor values >1 are oppressive and easily down the entire zoo archetype.
The also released some card changes to accompany the PTR testing, but even a cursory review shows that many of these were just quickly released to help collect data on armor 2.0. It's clear to me that the focus of this test is the mechanic not the cards. Also, devs confirmed in discord that they didn't implement all the balance changes for armor cards that they have planned. Other signals that the card changes are secondary: venerable paladin. Gives armor to strongest unit, but killing the paladin now removes armor.
OK, so we'll give them some slack on a rushed card balance job. As long as they clean it up on the second time around. What worries me more is that they have ignored a far superior solution to armor.
A better solution
Armor should be capped at 1 and not degrade. Just like frontline, blitz, twinstrike, deadly, etc., you don't stack armor. You just have it or you don't. Naturally, cards that currently have >1 armor will need extra xp or other perks to compensate. Aspect of the Pangolin needs to be changed to give armor to multiple creatures instead of a stack to a single one. These are easy changes.
Importantly, 1 armor is a great attribute for cards but is manageable to play around for all archetypes. There is lots of room for effects that add/remove the armor attribute just like cards do for frontline, backline, etc. Deadly creatures see increased value against 1 armor creatures.
Most importantly, this solution is a mechanic that cannot be made unintentionally OP by some future card combo. I hope devs consider this instead.
Problem with current 2.0 mechanic
The fundamental problem with armor 2.0 is that it nerfs most armor cards in order to preserve >1 armor on just a few cards. This creates a need to rebalance almost all the armor cards.
Take Guild Enforcer. It's a strong card, but make it's one armor degradable, and it takes a huge value hit. Ditto Bronze Gate, and they had to try and compensate Gate by adding HP. Having 1-armor creatures now losing armor makes the "Armor 1" text worth a lot less and throws off many balanced cards.
All this so poly and pangolin can keep their armor stacks?
Conclusion
I have a lot of faith in the balance team, and I think their PTR results will show them exactly what I've outline above. Don't forget, they tested their sleep 2.0 changes and then canned them based on PTR results. I expect to see something similar here. Fingers crossed they try the above solution next.