How do I stop CPU stuttering in Expeditions: Rome battles?

While commanding Roman legions in large-scale battles, I noticed CPU temperatures spike from 62℃ to 91℃ per AIDA64, causing severe frequency fluctuations and immersion-breaking stutters. I tried setting the fan mode to full speed in BIOS, but the noise was like a helicopter taking off while temperatures still lingered around 88℃, which was incredibly inefficient. I used the GamePP Fan Curve Configuration Panel to sharpen the speed slope between 75-85℃ and forced full speed at 90℃. Core temperatures dropped to 78-82℃ per HWInfo64 and frequencies stabilized at 4.2-4.4 GHz per CPU-Z.