Why does Where Winds Meet drop frames during dense combat scenes?

It was ironic that with top-tier RAM, facing a group of enemies caused my frame rate to plummet. I tried manually setting CPU affinity in Task Manager, but that caused the game to crash to desktop immediately. I used the GamePP Process Priority Manager to set the game to Real-time priority and killed all useless background services. Frame generation intervals converged to 8-11ms per RTSS, memory latency hit 112-128ns via AIDA64, and temps were 58-64℃ per HWiNFO.