Yeah, I think it adds like +1 per level of poison damage. Obviously you'd have to really stack it. And yes, I've used more than a good few poison grenades in my solo rogue play through. I might have just been RNG lucky though.
I feel like Act 1 is just too early to really judge zombie since it requires building around it and gearing up your party around it to make use of it. It's just a highly specialized party composition and tactics to make it shine.
I wouldn't be surprised though if the people you're working with just want to zombie to be immune in second part to all the poison while gaining tactical advantage in part 1. Your kind of stuck between two rocks. There's no good way to deal with your situation except to gear up multiple characters with zombie and outfit them all with all the poison methods you can. Not ideal I know. Technically if everyone in your party had zombie you could still do what you said but with poison/blood pools
the only difference is change out bless with contaminate. Against non zombies that's a bonus of stunning and poisoning enemies. And while they're stunffend you can move back and set them on fire before repeating the event with another character and then hitting them more fire. Theyll be stunned -> poisoned -> burned/exploded and then you repeat if you want with another character not on cool down. Also any additional all posion skills or grenades or wand/staff attacks with cause explosion while they're burning. There's also the fact that you can ignite poison by dropping a candle.
Also, doesn't being poisoned from food heal you? Or poisoned potions? I know of a poisoned potato.
