I've killed boars with 70 UA.
I start out on Oak Stance maneuver since one hit from it cuts down my def to 51~ on any other stance than Oak or Bloodlust. I use Float like a Butterfly to keep the advantage on neutral for now, and gain IP from DoG stance after regaining all my def. Build up IP by switching from Bloodlust, Oak, and DoG, then start switching to Dash and Skuld so as not to keep giving the boar IP. Opp Knocks, not completely necessary but sure makes things faster, then Knock Out. After that, even at 15~ attack, I simply use Knock Out again and it's dead.
All in all I think it's pretty safe way to kill boars as long as you don't jumble up on your stances. I've done it several times without armor as I was trying to build myself a cuirass then.
EDIT: Sometimes I initiate using CDTT just to make life a little easier.