As nouns the difference between crew and herd
is that
crew is a group of people (often staff) manning and operating a large facility or piece of equipment such as a factory, ship, boat, or airplane while
herd is a number of domestic animals assembled together under the watch or ownership of a keeper.
As verbs the difference between crew and herd
is that
crew is to be a member of a vessel's crew while
herd is to unite or associate in a herd; to feed or run together, or in company.