After battle in most countries in the past, you either lived or died as one cohort. However, the Romans had enough patients over a continuing period of time to

After battle in most countries in the past, you either lived or died as one cohort. However, the Romans had enough patients over a continuing period of time to perfect plastic surgery. So I think you're confusing emergency surgery and piercings with the art of plastic surgery. If you think anatomical knowledge was universal, that's not true either. Japanese doctors were ashamed when they saw the first anatomy book - they had known nothing beforehand. The US had to dig up bodies from graves at night for decades to draw those books.