Be careful about switching followers. Apparently UESP found ANOTHER bug with them - you know how they have invisible 'default' equipment that they wear and you can't remove? Well, whenever you recruit a companion, the game spawns a copy of their default equipment in the hidden inventory. Bad part? These invisible items DO count towards weight limit, meaning if you repeatedly hire the same companion, their encumbrance limit will get lower and lower, making them useless even as pack mules.