You
seem
to
have
the
terms
castration
and
emasculation
mixed
up.
To castrate a man, you only have to cut off his testicals. Castrating a male has absolutly nothing to do removing his penis. Now to emasculate a man, you just have to cut off his penis. Once a surgical knife gets involved, they won't be attached to each other for very long.
If this doesn't make sense to you consider this: You can cut of a person's thumb or you can cut off his pinky finger, you don't need to do the latter to do the former or vice versa. Cutting off both is not the same thing as cutting off just one of those digtis.
Jeremy