@Joshua-Young You can use the approach outlined above. There are a few other ways to do this as well.
The syncing btw environments could also be accomplished in many ways using ArcGIS. Whatever works for you and your organization is best. For example, using ArcGIS Data Pipelines to sync the layer information between AGOL and AGE. ( This syncing could also be done via python scripting, using an ArcGIS Notebook, and a variety of other ETL\sync workflows.)
A tip for identifying the internal and external lineage of apps would be to use the ArcGIS Solution Diagram and help documentation to understand public facing maps, apps, and layers, as well as what is truly internal as well.
AGOL Assistant works well to "swizzle" layers and item ids and layers, especially when the schema's are the same.
One thing to consider when swapping layers, any layer that is using the Living Atlas should not be swapped because the id is the same for AGOL and AGE. For example, in Emergency Management Operations we have the USA structures from the living atlas and that id wouldn't need to be switched. This isn't always clear in the code.
Another tip to think about, look at the version of the solution item in AGOL and the version of Enterprise you are using. Matching solution item version means the included layers, maps, and apps are the same in the majority of cases. If the versions are out of sync then using the release notes at the bottom of the intro help topic will give you a better understanding of what could be different and identify any adjustments that will have to be accounted for.
