- Bea, getting two attacks a round with her magical flail and one with the shortsword, assuming she hits with every blow (which is not unlikely since she gets +7 or +8 to hit), will do an average of 28 points damage a round. Double that if she doing her superheroic enemy-blender "Combat Surge" thing.
- Roe, whacking twice a round with her great-axe, does an average of 22 points a round. Again, double that if Surging.
- JZ, assuming she's doing a puny 1st-level version of Dissonant Whispers, adds another ten points or so. Up to 18 points with a good roll, more if she uses a higher-level spell slot.
So, on an average combat round, the party is dishing out 60 points of damage a round, and up to double that if they're rolling well. If the fighters are Surging, the average party damage goes up to 110 points, and possibly (though improbably) as much as 220. Bloody hell. And if anything, the situation is only going to be getting more imbalanced as they rise in level.
Even HUUUUUUUUUGE critters seldom have more than 100 hitpoints, or maybe 120, and most have considerably fewer. Pretty much anything that is whackable is going to be mince if it makes the mistake of getting anywhere near our lovable gang of mincing machines.
Clearly, big hulking brutes of monsters are just not going to be an effective challenge when they can be swatted aside without Our Heroes even raising a sweat. I shall have to get a lot sneakier. And fiercer.