Hi Kelly
I have a few maps that include editing done by multiple people. One example that might be of interest to you is a map for our park mowers where each mower has their own set of areas given to them, they then edit the record with the completion time/date after they have mown. This can result in multiple people editing at the same time. I have the information within all within the same feature class, but I have a field for the staff member assigned (alternatively it could be a field for your defined areas). To make it easier for them I have copied the layer for each of the staff and then set up a filter on each of the layers to show only the relevant ones for that staff member (for you this could be the relevant area). By default I have these all turned off so that they have to purposefully select their area. If you were looking at the spatial side as well you could include specific bookmarks to help quickly navigate to the right area.
I haven't come across any problems with multiple editors and I find that the editor tracking and archiving within AGOL has covered most of our needs.