Yeah those are the ones. I'm a rogue, Eder, Pallagina, the barbarian, the priest, and the druid. Sorry it's early and I've temporarily forgot people's names.
They do mainly pierce damage so consider stacking some DR against that, you can get it to 30 or more with plate armour and some spells. Give Pallegina the blunting belt, and have the priest use Armour of Faith and the Druid use Woodskin. (DR buffs to specific types like Woodskin will stack with "general" DR buffs like Armour of Faith.)
Also there's a few things you can do about the blow dart paralyze. You can remove it with Suppress Affliction and Liberating Exhortation but it's kind of spammy and so better to resist it the first place. It's actually an effect of poison type, so the druid level three spell Purge of Toxins will make you immune to it. You probably want to cast it on your backline, keep them out of sight at the start of the fight to get it off in time.
Also you can look in the crafting menu there's a level 2 scroll called Scroll of Protection, it won't make you immune but does reduce the paralyze duration and effects the whole party.
Also the lizards don't have great defenses or immunities themselves so consider just using AoE disables against the large groups. That's harder without a wizard, but if you look in the crafting menu you might be able make scrolls of confusion (level 4). These can make a huge difference.