IIRC there was one battle where Chinese soldiers fought Romans used as auxiliaries in Central Asia during that timeframe. The Chinese soldiers won. The question would be whether the Chinese weakness in terms of court intrigue or Roman weakness in terms of civil war-as-succession would be the more fatal weakness.
AFAIK, it's an apocryphal story based on a Chinese account of soldiers who fought vaguely like a Roman army. They could have just as likely been Soghdians or Daylamites.