Problem is that critters who can be enslaved use different type of body then player chars few exception are there like male trapper, male bandit and combat slaves, but the other ones have looks that would make armor wearing strange. No chance something like this would happen.
On the note of better weapons some of the slaves do able to equip those weapons combat slaves have all animation types for example its a different thing they ain't so skilled but then again they are not trained mercenaries.