Unless you want to continue talking in hypotheticals, and quibbling over slight differences, can you give us some hard, fast examples of:
What you fought,
What your party's level and makeup are, and
What died first and what you had to just stand around hacking?
Frankly, I'd prefer to talk in hypotheticals, as I think it's relatively safe given the consistent fact of monsters with lots o' hit points and low damage-dealing.
I think the situation is roughly analogous to the following:
Let's say that we have a dice-roll-off -- I roll a d6 and you roll a d8. A '4' counts as a 'hit' for either of us.
Scenario #1: I have to 'hit' you 3 times before you 'hit' me 4 times.
Scenario #2: I have to 'hit' you 9 times beore you 'hit' me 12 times.
I think I'm at a general advantage in this contest -- I'm going to win this little battle the majority of the time. But the number of times I win Scenario #2 is going to be a *much* greater percentage than I win Scenario #1.
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However, because you're curious, the battle was an 11th level party (goblin rogue, dragonborn paladin, human warlord, human wizard, and a warlock, I think) against three shambling mounds, four vine horror spellfiends, and a Briar Witch Dryad. The Dryad & company ended up attacking all from the same direction -- an early Wall of Fire and Ice Storm successfully immobilized/slowed a couple of Mounds, allowing the very cheaty goblin rogue + his help to take out a good chunk of mound hit points. The monsters were absolutely a threat -- the paladin was bloodied and swallowed into a mound (best character for that to happen to by far, luckily) and the warlord and rogue were also bloodied along the way, but even so, after a point it never felt *dangerous* -- really, after the Wall of Fire went up and the two mounds hit by the Ice Storm were immobilized/slowed. After all, even on a successfuly hit, the worst that can happen is that a monster takes away 15% of your starting hp.
BTW, the brutes went down first, followed by the vine horrors; the dryad tried to get away, but just for closure's sake Wizzy the Wizard did a little Arcane Gate action and we caught up with her. I think a lot of this is moot, though.