Sure, dark horses arose occasionally in martial bouts. There were examples of peak emperor realm cultivators defeating great emperors. The rarity didn’t make it impossible. There were always some unique geniuses that conquered in the face of adversity. Some even performed reverse sweeps.
However, such occurrences were fairly rare as a whole. Whenever an instance of this did occur, it would be widely publicized as a story to encourage the weak. They were usually labeled miracles, and rightly so.
Pill King Hui was a master of many subjects, but he was no miracle-maker when it came to martial dao. More importantly, Emperor Peerless wasn’t a great emperor fresh into his power. His fame was long-standing and well documented. The great emperor distinguished himself even amongst his peers. How could a man who led the wandering cultivator community be so easily defeated?
Pill King Hui had perhaps entertained delusions of grandeur before the fight...