B4: The Lost City is a classic module for D&D. At one point it (in)famously stops giving full description of the rooms but instead lists monsters in each area and tells the DM to figure out why they're here themselves. Once the reprint will show up in new anthology, I'm sure people who complain online whenever WotC uses "ruling not rules" or "DM decides" or "these parts were left for the DM to fill in" in their design (and then continues buying WotC books to keep bitching and doesn't touch 3rd party or other games for some reason) is going to be normal about it. /s
That sounds like a party composition problem, then. Don't everyone play ice mages and then walk into a volcano.
Sounds like monster creation rules need to be figured out before publishing the books, then.
Again, monster creation rules should be reliable. And they shouldn't include context buffs that absolutely wreck the power curve.