Yoshi P talks about Warriors- from Producer Letter Live @ TGS

[Dhex]

Parry is a completely separate stat from Dex that does not modify that number in any way. The rate at which you parry is directly modified by dex, and then again directly modified by the stat "parry". Dex does not modify "parry". The two together modify your rate of parry % chance across all responses to auto attack.

Either way stacking DEX is still asinine. Nothing at endgame is going to give Warrior DEX at lv50 - unless you're suggesting we should go buy Darklight's Aiming set - in which case you rob yourself of either +VIT +PARRY or +STR +CRIT depending on your opinion which are more important stats. By lowering Parry you're lowering the effectiveness of the DEX you add - by sacrificing STR you're lowering the Parry mitigation - by lowering VIT you're reducing your overall HP pool. Are you going to meld a significant amount of DEX? Allot your stat points to DEX +20? This would make my STR/DEX equal at 203 each at lv50 (with weapon stats removed).

It's pointless to mess with DEX in my opinion - it does nothing to actually bolster a Warrior's eHP.