What were the Eunuchs exactly!?

[Robert]

Ouch, that sounds like bad odds. Hmm, wonder is the same was true with oxen and horses. Doubt it very much. The procedure itself is not all that complicated, as the doctor Paul demonstrates. He uses two cuts, though.
So I think the high toll described by Justianus is either a means of getting the law passed more easily or they had some butcher performing the castrations, the subject dying of shock.