It also works for 2-handed weapon users as each hit from a split/swing etc will add a stack of head hunter. I guess the main question is if you can find the spare perk points, really.
If I am not mistaken, 2H weapons (except polearms and longaxes) hit both head and body at the same time, so increasing head hit chance with them is pointless.
Not sure how their area attacks work however.
