How many crew members load and offload luggage on an Airbus A380?
The Airbus Airport and Maintenance Planning documents note that:


  Actual times may vary due to each operator's specific practices, resources, equipment and operating conditions.


That being said, if everything is going smoothly, typically it's 2-3 operators per door.

One of the differences between an A380 and say a 767 is the number and size of containers. The rest is mostly the same. Below is a breakdown from a paper on the A320:


  The first operators' categorization that we had done was simple: belt loaders and cargo loaders, with reference to GSE. Usually, this is how airlines categorize their operators. Moreover, this categorization has a standard number of operators needed per GSE depending on its positioning:
  
  
  2 operators per Cargo Loader for the main cargo compartment;
  3 operators per Belt Loader for the main cargo compartment;
  2 operators per Belt Loader for the bulk compartment.
  
  
  However, this categorization is far too simple because there are more people than cargo and belt loaders involved in the cargo handling, for example tractor drivers and container loaders at the airport terminal. For this reason, Airbus ground handling operator's categorization has been used. This categorization divides the operators in:
  
  
  Semiskilled: loaders and cleaners.
  Skilled: bus drivers, refuelling staff, in general all equipment drivers.
  Highly skilled: boarding bridge operators, ramp agent, push-back operator.
  


(pegasus-europe.org)

As you can see from that paper, it's not just the number of operators at each door, it's a big system, combined with different hiring practices and different operators' methods, there is no one answer.


(Airbus)

Above shows an A380 schedule for a 90-minute turnaround since you seem interested in streamlining this process. Note the refueling start/finish and check this post. Passengers are typically boarded after the refueling is finished, otherwise it's a hassle that even includes alerting the fire service to be on standby.

Loading the cargo/passengers more quickly won't solve the A380 problems you asked about in recent posts.