In light of the events of universalization of sets bonusses, it would be very timely to pay attention to the bonuses of the 'Z'en's Redress' set.
In that moment:
(2 items) Adds 129 Magicka Recovery
(3 items) Adds 129 Spell Damage
(4 items) Adds 1096 Maximum Magicka
An example of how this could be done:
(2 items) Adds 1487 Offensive Penetration
(3 items) Adds 129 Spell & Weapon Damage
(4 items) Adds 657 Critical Chance
As you can see, this makes the set universal for both mage & stam. And stamina raids just suffer because of the difficulty in implementing all the support sets available to mages.