Why do loading stutters keep happening in Expeditions: Rome?

I assumed my large 4TB drive was failing because map switches caused visible hiccups. I ran a 2-hour DiskCheck scan, which only worsened the frame drops and added zero value. GamePP Resource Scheduler changed everything when I set the game process to 'Realtime' and disabled Windows Search indexing. Task Manager showed I/O throughput climbing from 200-300MB/s to 550-600MB/s. Latency dropped below 2ms, and map loading time cut down to a smooth 3.5 seconds.