Not sure what is your big deal with oil. Sure, is surpasses protecting, but the slow will never be the reason to lose. Thanks to magic armor, electric and burning surfaces are less of a threat than in D:OS 1. If you have enough magic armor, you can walk through them with out any care. In D:OS 1 you always needed to avoid them, if you weren't immune. If your team isn't grouped up, oil will often only affect one or two of your members and there are skill to counter it anyway like Haste. The big problem about the crocodiles was never the oil, it was the teleport, the heavy bite attack and the chance of getting feared, with hardly any magic armor to be protected of fear.
You're right, it's not so much about the difficulty. My main problem is that it's tedious facing that exact same identical enemy tactic in so many of the fights.
Every one of those fights I listed was an early game fight, where you're not likely to have much magic armor at all. This game doesn't have formation options to spread out your team, so avoiding being grouped together is largely dependent on terrain and initiative.
Also neither A nor B have any kind of fire attack for themselves, C for sure has and D not sure.
A and B don't have fire, but if the houndmaster's oil raduis hits the torches around, that's instant fire. All the oil spreading much makes starting out as a Pyromancer (or using any fire-based attack, really) a foolish idea.
