Ok, I've tried to put a friend in wardrobe and have them control an origin character instead, but the result was a little weird.
Here's what happened.
I put my friend's character in the wardrobe before he joined, and left 1 origin + 3 customized chars in the party, to see if he would be able to control the origin character.
Then I asked my friend to join. When the friend came in, the game auto-assigned one of the other customized characters to him. I then assigned the origin character to that friend and he could play with it, but I couldn't remove the customized character from his tab, it got stuck to him.
Then I asked him to close game to main screen and I put all customized characters into wardrobe, filling the party with origin characters. I was hoping one of those would be assigned to him. But when he joined, the game pulled his customized character from the wardrobe and kicked an origin char out of the party =\
Sigh... we just wanted to be able to do the companion side quests even when there are 4 players online. Withers wardrobe seemed like an opportunity, but no game =\
