It's like this, schee?
With Counterstance - 600 damage per hit average, 1% chance of being one-shotted by a triple attack that goes uncountered even with capped counter rate. 10% chance of being killed by a quick uncountered DA + TP move or 2x uncountered TA + TP move.
Without Counterstance - 300 damage per hit average, 0% chance of being oneshotted or killed with TP+DA combos.
You may argue that you take less damage on average with counterstance up, but you can't really argue that your odds of being oneshotted are lower. Unless you use Counterstance, the Hydra is incapable of doing enough damage to eat through your HP before your healer can get cures off. (Unless you're a taru Q.Q; )
XI Wiki


