The purpose of the enumerators is to purely collect data. I would say creating 2000 accounts would definitely be unnecessary and laborious since you have to create each one of them uniquely and share the project with each of the 2000 accounts.
My suggestion would be to create a single account or some few accounts e.g. for each continent or region.
I believe your users will be using unique data collection devices. Ordinarily, I would have used the UUID for each device. However, since this is not reliable in all scenarios. I would recommend you generate unique IDS for the 2000 users, using a particular random system and then distribute this to them. You can then use this unique ID to be able to identify the person collecting the data. From experience, if this is tied to a reward system, the compliance is always higher.