Spiders are small and consist mostly of mouth. They're not very good fighters, so maybe they could have additional function- something of a cheaper Lazy Forager.
You could give them an item you wish them to pick up, fe: a log, which will make the spider seek the closest one and drop it off near the player. It would bring the items one by one, player still having to pick them up.
I just think it could be a nice little addition, as they're the only followers Webber can have and he needs support in things other than battle as well.