Not sure if this mod caused the bug or if it's just Saints Row fun-time (these are the only mods I'm using) but Oleg seems to be rather happy picking up baseball bats from somewhere and they make his arms go crazy, this prevents him from using his brute attacks since he's technically swinging a bat and it makes him rather useless. Johnny Tag and the other Brutes don't seem to pick up baseball bats or penetrators, just Oleg.
Oh and is your character supposed to be naked after disabling the avatar morph? XD