WH passive never had void until we added it. Defense is a fairly useless stat and not something I would base anything on. Wh has the higher defense in the game, roughly like 1k more than defender. Wh void is only a few hundred less than defender. Wh has actually been one of the most game breaking classes end game which caused a lot of changes on all classes around accuracy, chacc, dot reduction, number of targets, target aoe, and dot damage.
The only buff they would get honestly would be their major mech skill. I am also the person who made all the wh builds on aeria as it is my favorite class besides medic lol.