I just did troll dungon on hard with 1 rest. pressed on because had only 11 rations, wasted every potion and wand of fireball and scroll of haste and hp potion and enlarged potion. cleared both levels until 3 branded trolls and final boss.
the big troll died of laughter. for some reason he was ignoring hold person. here's a thing about laughter - it locks monster in a particular animation, and it takes time for him to fall down and then get back up. And that is where you waste the motherfucker. Level 7 party.
Jubilost proved essential of course.
Here's a thing about this fight on Hard+. You might want to kill actual kobold first because he buffs the boss, but he is a mastah +22 concentration defensive caster and fully buffed +concealment +decent hp, so unless you have some sort of 100% way of dealing with him (maybe you're lucky with dispels, idk) trying to kill him is a waste of time. And splash damage from acid flask did trigger his concetration checks anyway for me.
Instead focus on the boss with as much damage as possible, and create an extra hp buffer through summons. Here there were some skelengtons and leopards and uberbuffed bear (splatted on the floor with giant trollclub on the picture, but he did his duty) for that. Then it's just maximizing damage. Sure Tartuk can paralyze you, but he may choose wrong targets and he also likes his prebuffing and magic missiles, and targeting your weaker characters, so you have the time. His Will save is strong but with both perks of spell focus Enchantment Lindzi eventually did her thing.