Fought him twice last night: J5 healer merc, 90 War mix hot 1-4 group and uf T6 raid, all others (90 clr, 90 brd, 90 mag, 89 sham) in hot T1-2 gear. Fight was much easier than king, however the adds can add up quickly. First go only 6 popped - war held agro on named focus on killing adds, group burned on named. Second go all burned on named, shorter fight, but had at least 10 adds pop. So, imo, there seems to be some variable to how the adds are popped. The adds have low attack (lots of misses) but can bring you low quickly if a couple get a lucky streak.
Honor Guard Gakd spawns on ledge above where the King spanws. 3 adds pop like every 20 or 30 seconds during the fight (a goblin warrior) and have low hit points. I kept mezzing the adds until he was dead. Ended up with 12 goblins when he died. They don't despawn and will camp your corpse. Dropped Silvery War Axe and Reis Leggings.