How to fix frame rate fluctuations in Expeditions: Rome battles?

I was so excited once I unlocked the power wall! Previously, during legion charges, frames jumped between 50-70 FPS. I first tried enabling 'Ultimate Performance' in Windows power settings, but the 65W limit was hardware-level, making software tweaks useless. I used the GamePP BIOS Load-Line Voltage Adjustment Wizard to set LLV to L2 mode and raised the power limit to 125W. Average FPS jumped from 62 to 94 per RTSS, and power limits hit 125W per HWInfo64.