Toughts about the armor system in hots:

I feel like the idea of armor or damage negation for tanks in general is a good idea, and healthy for the game. On the other hand giving passive armor for heroes "to counter a specific thing" is imo unhealthy. Not only is it unhealthy, but also hard to know, since it isnt visible that the target takes less dmg.

To come with an example of what i think is "good armor", then muradin´s dwarf toss gives him 25 armor (so it can be used as an engage tool and take less dmg), but at the same time there is no visible factor to that armor, so only players who knows he gain armor from jump will understand why they deal less dmg to him.

What can the enemy mage do to counterplay anub with spell dmg reduction? Not much tbh, you will deal less dmg to him no matter what.

I like the idea of having a hero that counter mages, but the reason why he counters them is mainly cuz he takes less dmg from them. I would love to see his lvl 16 talent "debilitation" (Enemy heroes hit by Burrow Charge have their spell power reduced by 50% for 4 seconds) being baseline, together with his Shield (w) taking less dmg from abilities. With that he would still be a "counter-mage" hero, but with counterplay. The enemy mage can try not to use the whole combo while anub have his shield up, and avoid getting into a position where anub can burrow charge him. I think that is a healthier way to implement armor, since it has playmaking for the tank and counterplay for the enemy team.

Even tho i would like to see more counterplay being enabled for armor, i still think the most important thing is visibility. It feels weird that you are taking less dmg without it being visible in any way (unless you press c and look at your armor).

Anyway, just my casual toughts about armor