I'm going to dump some more change into this conversation.
"Multi-classing" as some here have called it is more prevalent in submarines, where crews are highly trained and the loss of one compartment probably means that whole section of the crew is dead. It's nice to have a few spares. In WWII it was said that each German U-boat crewman knew how to do the job of every other crewman on board his submarine, and they only earned your Dolphins badge (think Able Seaman) until they could demonstrate this to an officer. They also had to re-qualify for each different submarine they served on.
Keep in mind ship design as well. Western ships tend to have so much crew because they're designed to be serviced and repaired at sea if need be. All of them are designed to be replenished at the very least. Also, fleets tend to keep large volumes of specialized technical staff on hand for things from fixing forklifts to supply organization. This is feasible because of the high degree of education available in the West and the typically higher level of motivation from volunteers.
Meanwhile, you have the Russian design mindset. Since Russia has a navy mainly made up of poorly educated conscripts (who are severely underpaid) their ships lack the highly trained technical staff required to service them constantly. Instead, these specialists are kept in naval bases and ships are used for relatively short-ranged missions before coming back to port. Because the ship isn't expected to do repairs underway this also allows Russian ships to be a lot smaller as systems are packed closer together without the engineering space to allow crewmen to service them efficiently.
Keep this in mind when comparing crew sizes as well. A navy is typically an extension of its home nations will and character and will be designed around such.
"Multi-classing" as some here have called it is more prevalent in submarines, where crews are highly trained and the loss of one compartment probably means that whole section of the crew is dead. It's nice to have a few spares. In WWII it was said that each German U-boat crewman knew how to do the job of every other crewman on board his submarine, and they only earned your Dolphins badge (think Able Seaman) until they could demonstrate this to an officer. They also had to re-qualify for each different submarine they served on.
Keep in mind ship design as well. Western ships tend to have so much crew because they're designed to be serviced and repaired at sea if need be. All of them are designed to be replenished at the very least. Also, fleets tend to keep large volumes of specialized technical staff on hand for things from fixing forklifts to supply organization. This is feasible because of the high degree of education available in the West and the typically higher level of motivation from volunteers.
Meanwhile, you have the Russian design mindset. Since Russia has a navy mainly made up of poorly educated conscripts (who are severely underpaid) their ships lack the highly trained technical staff required to service them constantly. Instead, these specialists are kept in naval bases and ships are used for relatively short-ranged missions before coming back to port. Because the ship isn't expected to do repairs underway this also allows Russian ships to be a lot smaller as systems are packed closer together without the engineering space to allow crewmen to service them efficiently.
Keep this in mind when comparing crew sizes as well. A navy is typically an extension of its home nations will and character and will be designed around such.