If you let something actually attack you in Melee, the brute will sometimes attack that specific foe - it's the same for all talisman summons, and necro familiars. They'll defend themselves, and attack whatever you attack in melee (by actually clicking on the target to initiate combat. If you just auto-defend, the summons will usually just sit and watch.
I think you might be able to use provo to get it and other things to fight each other.