ultimately I'm curious what works better in play, lowering offense with exhaustion or defense.
right now the playtest version is offense, no loss of defensive power, just offense. So a highly exhausted character isn't going to get gacked, but probably not going to be able to contribute to the fight very well either....which is boring, the worse thing you can do to a player. Previously they could try things like grappling but those are attack rolls now as well.
If you nerf defense, yes you create death spirals, but at least that's interesting. The player has to take a bigger risk to adventure, that to me is more "heroic" than being fully defended up and sit there ineffectually wailing on the enemy