We played against the Gargant tonight. 3 way with Sep Guard, Thorns of Briar, and Cursebreakers. With all the undead models there was always someone for him to attack so no regeneration. He was always able to complete his movement easy enough so no bellow either. Even with some fighting amongst ourselves we were able to take him out by the end of turn 3. Not nearly as difficult as I first imagined him to be. Maybe with smaller warbands he would be able to heal himself more often, but it just seemed like someone was always there wailing on him trying to get glory. It was a nice change of pace, but definately not something we will be doing often.