"Few people can guess how despondent one has to be in order to resuscitate Carthage." - Flaubert
Technically this is historical fiction, based on a few brief chapters of Polybius that could be read in the space of a lunch break. But the sensibility is closer to a fantasy novel, (a pulpy one, even) all about conjuring the atmosphere of a lost world.
The plot: after losing the second Punic war to Rome, the geniuses running Carthage try to haggle down the backpay owed to their mercenary army. They get understandably upset, have a big orgiastic party, and get exiled to a neighboring city where their resentments are whipped up by a crafty Roman ex-slave named Spendius and his himbo sidekick Matho. A Curb Your Enthusiasm style series of misunderstandings and accidents escalates to a multi-year war of extermination and hundreds of children getting sacrificed to Moloch before the mercenaries finally get wiped out.

I'm really glad you made that blood meridian reference because it was the first work that came to mind when I was reading this