What determines feature layer order when publishing service from GDB upload?

[GB_MattPanunto_GISS]

When publishing a service via GDB upload, I assumed feature layer order was determined by the alphanumeric sorting of GDB feature class names, but this does not seem to be the case. My GDB has 3 feature classes, a Point, and two Polygon feature classes. They are named:

"A" (Point)

"B" (Polygon)

"C" (Polygon)

When I upload the GDB to publish the service, the resulting layers are in  B-C-A order. I want them to be in A-B-C order. How do I do that?

[MatthewBrown8]

Following additional testing using ArcGIS Enterprise 10.7.1, I was unable to reproduce these results. As such, the observed behavior may be limited to ArcGIS Online.

Regards,

[DavidTillberg_community]

Thank you for this.  I would add that the order of the service indices is also the same as returned by arcpy.ListFeatureClasses() for Feature Layers, continued by arcpy.ListTables() for tables, and that finally tables that define M -> M relationships are listed in order they were created.