I though that Demandred commented that the fade's swords actually failed after a time and had to be replaced, hence the difficulty the lack of human victims were causing i.e. the stockpiles were running low.

As for were the swords used in the War of Power I would guess they came in later. At the begining they probably were using high tech weapons and unless the Dark One gave a users manual on evil smything 101 the forsaken would probably have had to experement and discover it was possible to take human souls and bind them to the swords.