Looking for help with creating a dashboard element that uses multiple layers to calculate a total count of data points. For context, we have a web map on ArcGIS Online being used for data collection with field maps. It consists of several layers related to different pieces of infrastructure being updated. The attributes of the layers themselves can't be altered so unfortunately creating a new calculated field or joins between the layers isn't a possibility. We are currently monitoring the progress of these updates through a simple dashboard that uses the indicator to show a count of each layer type being updated. While this is serviceable for the time being, it creates unneeded clutter in the dashboard as we are less concerned about individual counts and instead the total count of updates. We'd rather have something more akin to a summary that's easy to glace at rather than layer specific information.
From what I can tell, I think we'd have to utilize arcade functionality in the dashboard indicator alongside "FeatureSet", but my arcade knowledge is limited at best. Any guidance would be greatly appreciated.