use any of the staffs I give him? even if I use console command removeallitems to get rid of his weapons, he'll punch stuff with this fists when out of mana.
edit: he'll use swords and other melee weapons no problem
This happened in my game, too, with both J'zargo and Onmund. As soon as I got a melee companion, though, they would equip the staves with no problem. No clue.