What hasn't been mentioned here at all concerning Defenders is that they on their own are a bad play. Most of them have 2 less power than their provision costs.
Also, most defenders have hardly any synergy and the synergy they have is limited to 1 archteype. Therefore, the player using a defender looses a turn in which the oponent can already set up an engine, which should count for something too.
And I know that both isn't true for the dwarven defenders, which is why he is that great.
Nonetheless, Defenders seem to be too strong at the moment and I see basically 4 options:
1) Higher provisions: Defenders should be a tech choice, so making them more costly should be a good idea.
2) Lower base power: Forces a rework of seize or seize will be even stronger against Defenders.
3) More purify: Something that needs to be done anyway regardless of defenders. Every faction should have purify options for most archetypes.
4) Make Defender an ability instead of a status: purifying a defender is currently a lot stronger than purifying anything else, this way purify wouldn't get too situational, while lock would be there for bigger effects. Would need a lock rework nonetheless (lock for X turns).
5) Restrict the number of allies: Restrict it to 1 or two on each side. Combined with being an ability, the reach could even be influentiable. (Barricade: Defend 2 adjacent allies instead of 1)
