Rule #1: Your loadout is set at the time the Guild Wars event start. Any changes after only apply to the rest of the game's stuff.
Rule #2: You are "using" the top 15 players in the guild's attributes, that are also "set" when it starts, on attack or defence. Whatever they were "wearing" is what you are wearing no matter what your individual personal armour is, after the start.
The only variation is when you start on Defence or Attack, personally, on "healing".
Hope that helps !
Last edited: Nov 28, 2015