All these armor pieces are for different enemy types, so the intellect might be on vex arms and maybe the discipline on the cabal arms . Each enemy type might rotate all its stats through the different pieces. Remember there are 4 armor sets for the POE, vex, hive, fallen, cabal What we know so far Vex head - strength Vex arms Vex chest Vex boots Cabal head Cabal arms Cabal chest Cabal boots Fallen head Fallen arms - strength Fallen chest Fallen boots Hive head Hive arms Hive chest - strength Hive boots For those confused about the 4 sets. One for each enemy types. 4 pieces for vex , 4 for fallen, 4 for hive , 4 for cabal The perks say equip before the round starts, so for example , it's a hive round so in airlock equip your 4 hive Poe armor, you complete it , go to airlock now it's cabal so while in airlock equip cabal pieces, you go in the area it says round 1 so your perks are now activated for that enemy type