It depends on the data collection task. If you can get it done with minimal effort, then you won’t need a lot of people. If data collection will take time, then you’ll want more people helping. An example would be if you had to spend a few minutes reviewing an application to determine if there were any errors and you had to review 100s of applications to get a good sample, then it’s a good idea to enlist more people.
Another example of requiring more people to collect data is if you have different locations as “stratification factors.” Then you’ll need operators at each location to ensure it’s a balanced sample. It all depends on the data being collected, the effort required for each unit and how to accommodate the stratification factors.